AU2006292106A1 - Aptamers to the human IL-12 cytokine family and their use as autoimmune disease therapeutics - Google Patents

Description

WO 2007/035922 PCT/US2006/037276 Aptamers to the Human IL-12 Cytokine Family and Their Use as Autoimmune Disease Therapeutics FIELD OF INVENTION [0001] The invention relates generally to the field of nucleic acids and more particularly to aptamers capable of binding to members of the human interleukin-12 (IL-12) cytokine family, more specifically to human interleukin-12 (IL-12), human interleukin-23 (IL-23), or both IL- 12 and IL-23, and to other related cytokines (e.g., IL-27 and p40 dimer). Such aptamers are useful as therapeutics in and diagnostics of autoimmune related diseases and/or other diseases or disorders in which the IL-12 family of cytokines, specifically IL-23 and IL- 12, have been implicated. The invention further relates to materials and methods for the administration of aptamers capable of binding to IL-23 and/or IL- 12. BACKGROUND OF THE INVENTION [0002] Aptamers are nucleic acid molecules having specific binding affinity to molecules through interactions other than classic Watson-Crick base pairing. [0003] Aptamers, like peptides generated by phage display or monoclonal antibodies ("mAbs"), are capable of specifically binding to selected targets and modulating the target's activity, e.g., through binding aptamers may block their target's ability to function. Created by an in vitro selection process from pools of random sequence oligonucleotides, aptamers have been generated for over 100 proteins including growth factors, transcription factors, enzymes, immunoglobulins, and receptors. A typical aptamer is 10-15 kDa in size (30-45 nucleotides), binds its target with sub-nanomolar affinity, and discriminates against closely related targets (e.g., aptamers will typically not bind other proteins from the same gene family). A series of structural studies have shown that aptamers are capable of using the same types of binding interactions (e.g., hydrogen bonding, electrostatic complementarities, hydrophobic contacts, steric exclusion) that drive affinity and specificity in antibody antigen complexes. [00041 Aptamers have a number of desirable characteristics for use as therapeutics and diagnostics including high specificity and affinity, biological efficacy, and excellent WO 2007/035922 PCT/US2006/037276 pharnacokinetic properties. In addition, they offer specific competitive advantages over antibodies and other protein biologics, for example: [00051 1) Speed and control. Aptamers are produced by an entirely in vitro process, allowing for the rapid generation of initial leads, including therapeutic leads. In vitro selection allows the specificity and affinity of the aptamer to be tightly controlled and allows the generation of leads, including leads against both toxic and non-immunogenic targets. [00061 2) Toxicity and Immunogenicity. Aptamers as a class have demonstrated little or no toxicity or immunogenicity. In chronic dosing of rats or woodchucks with high levels of aptamer (10 mg/kg daily for 90 days), no toxicity is observed by any clinical, cellular, or biochemical measure. Whereas the efficacy of many monoclonal antibodies can be severely limited by immune response to antibodies themselves, it is extremely difficult to elicit antibodies to aptamers most likely because aptamers cannot be presented by T-cells via the MHC and the immune response is generally trained not to recognize nucleic acid fragments. [00071 3) Administration. Whereas most currently approved antibody therapeutics are administered by intravenous infusion (typically over 2-4 hours), aptamers can be administered by subcutaneous injection (aptamer bioavailability via subcutaneous administration is >80% in monkey studies (Tucker et al., J. Chromatography B. 732: 203 212, 1999)). This difference is primarily due to the comparatively low solubility and thus large volumes necessary for most therapeutic mAbs. With good solubility (>150 mg/mL) and comparatively low molecular weight (aptamer: 10-50 kDa; antibody: 150 kDa), a weekly dose of aptamer may be delivered by injection in a volume of less than 0.5 mL. In addition, the small size of aptamers allows them to penetrate into areas of conformational constrictions that do not allow for antibodies or antibody fragments to penetrate, presenting yet another advantage of aptamer-based therapeutics or prophylaxis. [0008] 4) Scalability and cost. Therapeutic aptamers are chemically synthesized and consequently can be readily scaled as needed to meet production demand. Whereas difficulties in scaling production are currently limiting the availability of some biologics and the capital cost of a large-scale protein production plant is enormous, a single large scale oligonucleotide synthesizer can produce upwards of 100 kg/year and requires a relatively modest initial investment. The current cost of goods for aptamer synthesis at the kilogram scale is estimated at $500/g, comparable to that for highly optimized antibodies. 2 WO 2007/035922 PCT/US2006/037276 Continuing improvements in process development are expected to lower the cost of goods to < $100/g in five years. [0009] 5) Stability. Therapeutic aptamers are chemically robust. They are intrinsically adapted to regain activity following exposure to factors such as heat and denaturants and can be stored for extended periods (>1 yr) at room temperature as lyophilized powders. CYTOKINES AND THE IMMUNE RESPONSE [00101 The immune response in mammals is based on a series of complex cellular interactions called the "immune network." In addition to the network-like cellular interactions of lymphocytes, macrophages, granulocytes, and other cells, soluble proteins known as lymphokines, cytokines, or monokines play a critical role in controlling these cellular interactions. Cytokine expression by cells of the immune system plays an important role in the regulation of the immune response. Most cytokines are pleiotropic and have multiple biological activities including antigen-presentation; activation, proliferation, and differentiation of CD4+ cell subsets; antibody response by B cells; and manifestations of hypersensitivity. Cytokines are implicated in a wide range of degenerative or abnonnal conditions which directly or indirectly involve the immune system and/or hematopoietic cells. An important'family of cytokines is the IL-12 family which includes, e.g., IL-12, IL 23, IL-27, and p40 monomers and p40 dimers. [0011] IL-23 is a covalently linked heterodimeric molecule composed of the p19 and p 4 0 subunits, each encoded by separate genes. IL-12 is also a covalently linked heterodimeric molecule and consists of the p35 and p40 subunits. Thus, IL-23 and IL-12 both have the p40 subunit in connnon (Figure 1). Human and mouse p19 share ~70% amino acid sequence identity and are closely related to p35 (the subunit unique to IL-12). Transfection assays reveal that like p 3 5, p19 protein is poorly secreted when expressed alone and requires the co-expression of its heterodimerizing partner p40 for higher expression. Together, p40 and p19 form a disulfide-linked heterodimer. The p19 component is produced in large amounts by activated macrophages, dendritic cells ("DCs"), endothelial cells, and T cells. Th1 cells express larger amounts of p19 mRNA than do Th2 cells; however, among these cell types only activated macrophages and DCs constitutively express p40, the other component of IL-23. The expression of p19 is increased by bacterial products that signal through the Toll-like receptor-2, which suggests that p19, and thus IL 23, may function in the immune response to certain bacterial infections. 3 WO 2007/035922 PCT/US2006/037276 [0012] One of the shared actions of IL-12 and IL-23 is their proliferative effect on T cells (Brombacher et al., Trends in Immun. (2003)). However, clear differences exist in the T-cell subsets on which these cytokines act. In the mouse, IL-12 induces proliferation of naYve murine T cells but not memory T cells, whereas the proliferative effect of IL-23 is confined to memory T cells. In humans, IL-12 promotes proliferation of both naYve and memory human T-cells; however, the proliferative effect of IL-23 is still restricted to memory T cells. Also, the action of IL-23 on IFN-y production is directed primarily toward memory T cells in humans. Although IL-12 can induce IFN-y production in naive T-cells and, to a greater extent, memory T-cells, IL-23 has very little effect on IFN-y production in naYve T-cells. A moderate increase in IFN-y production is observed in memory T-cells stimulated by IL-23, but this effect is somewhat smaller than that resulting from stimulation with IL-12. [00131 Thus, IL-23 has biological activity that is distinct from IL-12, however both are believed to play a role in autoimmune and inflammatory diseases such as multiple sclerosis, rheumatoid arthritis, psoriasis, systemic lupus erythamatosus, and irritable bowel diseases (including Crolm's disease and ulcerative colitis), in addition to diseases such as bone resoprtion in osteoporosis, Type I Diabetes, and cancer. IL-23 AND/OR IL-12 SPECIFIC APTAMERS AS AUTOIMMUNE DISEASE THERAPEUTICS [0014] While not intending to be bound by theory, it is believed that IL- 12 and IL-23 are involved in multiple sclerosis ("MS") pathogenesis. For example, p40 levels are up regulated in the cerebral spinal fluid of MS patients (Fassbender et al., (1998) Neurology 51:753). In addition, an anti-p40 mAb has been shown to localize to lesions in the brain (Brok et al., JI (2002)169:6554). Furthermore, lower baseline levels of p40 mRNA have been shown to predict clinical responsiveness to IFN-p treatment (Van-Boxel-Dezaire et al., 1999). Thus, a knock-down of both IL-12 and IL-23 via p40 might ameliorate the symptoms of MS. In fact, anti-p40 antibodies have been shown to significantly suppress the development and severity of Experimental Autoimmune Encephalomyelitis ("EAE") in mice (Constantinescu et al., JI (1998) 161:5097) and in marmosets (Brok et al., JI (2002)169:6554). 4 WO 2007/035922 PCT/US2006/037276 [00151 Despite the evidence showing that knocking out both IL-23 and IL-12 suppresses the development and symptoms of MS, there is strong evidence that IL-23 is the more important of the two in MS/EAE pathogenesis in mice, as shown by the effects of IL- 12 and IL-23 knock-outs on the EAE mouse model. (Cua et al., (2003) Nature 421:744). For example, EAE can occur in p35 knockout mice, but not p19 or p40 knock-out mice (Cua et al., (2003). Expression of IL-23 but not IL-12 in the CNS rescues EAE in pl9/p4O knock out mice, although over-expression of IL-12 exacerbates EAE, so IL-12 seems to play some role in general TH1 cell development and activation (Cua et al.). In humans, over expression of p 4 0 mRNA but not p35 mRNA has been observed in the Central Nervous System (CNS) of MS patients. [0016] In addition to playing a general role in activating ThI cells, IL-12 may be more important for fighting infection than IL-23. In mice, a p19 knock-out induces classic Thl cell response (high IFN-gamma, low IL-4), whereas the response in p35 and p40 knock-out mice is restricted to Th2 cells (low IFN-gamma, high IL-4) (Cua et al.). Additionally, p19 knock-out immune cells produce strong pro-inflammatory cytokines, whereas p40 knock out inunune cells cannot. Lastly, p40, IL- 12R3 1 and IL- 12Rp2 knock-out mice are susceptible to a variety of infections (Adorini, from Contemporary Immunology (2003) pg. 253). Thus inhibiting IL-23 specifically through aptamer therapeutics may effectively fight IL-23 mediated disease while leaving the patient more able to fight infection. [0017] Both IL-23 and/or IL-12 have been implicated in rheumatoid arthritis as a promoter of end-stage joint inflammation. While not intending to be bound by theory, it is believed that IL-23 affects the function of memory T-cells and inflammatory macrophages through engagement of the IL-23 receptor (IL-23R) on these cells. Studies indicate the IL 23 subunits p19 and/or p40 play a role in murine collagen-induced arthritis ("CIA"), the mouse model for rheumatoid arthritis. Anti-p40 antibodies have been shown to ameliorate the symptoms in murine CIA and prevent development and progression alone and when combined with anti-tumor necrosis factor (anti-TNF) treatment (Malfait et al., Clin. Exp. Immunol. (1998) 111:377, Matthys et al., Eur. J. Imnmunol. (1998) 28:2143, and Butler et al., Eur. J. Immunol. (1999) 29:2205). Furthennore, p19 and p40 knockout mice have been shown to be completely resistant to the development of CIA while CIA development and severity is exacerbated in p35 knock-out mice (McIntyre et al., Eur. J. Inmunol. (1996) 26:2933, and Murphy et al., J. Exp. Med. (2003) 198:1951). Thus, the aptamers and 5 WO 2007/035922 PCT/US2006/037276 methods of the present invention that bind to and inhibit IL-23 are useful as therapeutic agents for rheumatoid arthritis. [0018] Both IL-23 and/or IL- 12 are also believed to play a dominant role in the recruitment of inflammatory cells in Th- 1 mediated diseases such as psoriasis vulgaris, and irritable bowel disease, including but not limited to Crohn's disease and ulcerative colitis. For example, elevated levels of p19 and p40 mRNA were detected by quantitative RT-PCR in skin lesions of patients with psoriasis vulgaris, whereas p35 mRNA was not (Lee et al., J Exp Med (2004) 199(l):125-30). In 2, 4, 6, trinitrobenzene sulfonic acid ("TNBS") colitis, an experimental model of inflammatory bowel disease in mice, treatment with an anti-IL- 12 monoclonal antibody proved efficacious in completely ameliorating/preventing mucosal inflammation (Neurath et al., J Exp Med (1995) 182:1281-1290). In another study which evaluated several different IL-12 antagonists in the TNBS colitis model, an anti-IL-12 p 4 0 antibody proved to be the most effective in preventing mucosal inflammation, thus implicating both IL-12 and IL-23 (Schmidt et al., Pathobiology (2002-03); 70:177-183). Thus, the aptamers of the present invention that bind to and inhibit IL-12 and/or IL-23 are useful as therapeutic agents for psoriasis and inflammatory bowel diseases. [0019] It is also believed that IL-12 and/or IL-23 play a role in systemic lupus erythamatosus ("SLE"). For example, serum obtained from SLE patients were found to contain significantly higher amounts of p40 as a monomer than serum levels of p40 as a heterodimer e.g., IL-12 (p35/p40) and IL-23 (p19/p40), indicating that deficient IL-23 and/or IL- 12 production may play a role in the pathogenesis of SLE. Thus, aptamers of the invention which enhance the biological function of IL-23 and/or IL- 12 are useful as therapeutics in the treatment of systemic lupus erythamatosus (Lauwerys et al., Lupus (2002) 11(6):384-7). IL-23 AND/OR IL-12 SPECIFIC APTAMERS AS ONCOLOGICAL THERAPEUTICS [0020] The anti-tumor activity of IL-12 has been well characterized, and recent studies have shown that IL-23 also possesses anti-tumor and anti-metastatic activity. For example, colon carcinoma cells retrovirally transduced with IL-23 significantly reduced the growth of colon tumors established by the cell line in immunocompetent mice as compared to a control cell line, indicating that the expression of IL-23 in tumors produces an anti-tumor effect. (Wang et al., Int. J. Cancer: 105, 820-824 (2003). Likewise, a lung carcinoma cell 6 WO 2007/035922 PCT/US2006/037276 line retrovirally engineered to release single chain IL-23 ("scIL-23") significantly suppressed lung metastases in BALB/c mice, resulting in almost complete tumor rejection (Lo et al., J. Immunol 2003, 171:600-607). Thus, aptamers that bind to IL-23 and/or IL-12 and enhance their biological function are useful as oncological therapeutics for the treatment of colon cancer, lung cancer, specifically lung metastases, and other oncological diseases for which IL-23 and/or IL-12 have an anti-tumor effect. [0021] There is currently no known therapeutic agent that specifically targets human IL 23. Available agents that target IL-23 include an anti-human IL-23 p19 polyclonal antibody available through R&D Systems (Minneapolis, IM) for research use only, an anti-human p40 monoclonal antibody which targets both IL-12 and IL-23, since both cytokines have the p40 subunit in common, and anti-mouse IL-23 p19 polyclonal and monoclonal antibodies, which target mouse IL-23, not human IL-23 (Pirhonen, et al., (2002), J Immunology 169:5673-5678). As previously explained, an agent that inhibits the activity of both IL-23 and IL-12 may leave patients more vulnerable to infections, and generally can pose more complications in terms of developing a therapeutic agent than an agent that inhibits only IL 23. Since there is evidence that IL-23 plays a more important role than IL-12 for autoimmune inflammation in the brain and joints, a therapeutic specific for only IL-23 may be more advantageous than an agent which targets both cytokines, such as the anti-p40 human mAb. [00221 Given the advantages of specificity, small size, and affinity of aptamers as therapeutic agents, it would be beneficial to have materials and methods for aptamer therapeutics to treat diseases in which human cytokines, specifically IL-23 and IL-12, play a role in pathogenesis. The present invention provides materials and methods to meet these and other needs. SUMMARY OF THE INVENTION [00231 The present invention provides materials and methods for the treatment of autoimmune and inflammatory disease and other related diseases/disorders in which IL-23 and/or IL- 12 are involved in pathogenesis. [0024] In one embodiment, the materials of the present invention provide aptamers that specifically bind to IL-23. In one embodiment, IL-23 to which the aptamers of the invention bind is human IL-23 while in another embodiment IL-23 is a variant of human IL-23. In one 7 WO 2007/035922 PCT/US2006/037276 embodiment the variant of IL-23 performs a biological function that is essentially the same as a function of human IL-23 and has substantially the same structure and substantially the same ability to bind said aptamer as that of human IL-23. [0025] In one embodiment, human IL-23 or a variant thereof comprises an amino acid sequence which is at least 70% identical, preferably at least 80% identical, more preferably at least 90% identical to a sequence comprising SEQ ID NOs 4 and/or 5. In another embodiment, human IL-23 or a variant thereof has an amino acid sequence comprising SEQ ID NOs 4 and 5. [00261 In one embodiment, the aptamer of the invention has a dissociation constant for human IL-23 or a variant thereof of about 100 nM or less, preferably 50 nM or less, more preferably 10 nM or less, even more preferably 1 nM or less. [00271 In one embodiment, the aptamer of the present invention modulates a function of human IL-23 or a variant thereof. In one embodiment, the aptamer of the present invention stimulates a function of human IL-23. In another embodiment, the aptamer of the present invention inhibits a function of human IL-23 or a variant thereof. In yet another embodiment, the aptamer of the present invention inhibits a function of human IL-23 or a variant thereof in vivo. In yet another embodiment, the aptamer of the present invention prevents IL-23 from binding to. the IL-23 receptor. In some embodiments, the function of human IL-23 or a variant thereof which is modulated by the aptamer of the invention is to mediate a disease associated with human IL-23 such as: autoimmune disease (including but not limited to multiple sclerosis, rheumatoid arthritis, psoriasis, systemic lupus erythamatosus, and irritable bowel disease (e.g., Crohn's Disease and ulcerative colitis)), inflammatory disease, cancer (including but not limited to colon cancer, lung cancer, and lung metastases), bone resorption in osteoporosis, and Type I Diabetes. [00281 In one embodiment, the aptamer of the invention has substantially the same ability to bind human IL-23 as that of an aptamer comprising a nucleotide sequence selected from the group consisting of: SEQ ID NOs 13-66, SEQ ID NOs 71-88, SEQ ID NOs 91-96, SEQ ID NOs 103-118, SEQ ID NOs 124-130, SEQ ID NOs 135-159, SEQ ID NO 162, and SEQ ID NOs 164-172, SEQ ID NOs 176-178, SEQ ID NOs 181-196, and SEQ ID NOs 203-314. In another embodiment the aptamer of the invention has substantially the same structure and substantially the same ability to bind IL-23 as that of an aptamer comprising a nucleotide sequence selected from the group consisting of: SEQ ID NOs 13-66, SEQ ID 8 WO 2007/035922 PCT/US2006/037276 NOs 71-88, SEQ ID NOs 91-96, SEQ ID NOs 103-118, SEQ ID NOs 124-130, SEQ ID NOs 135-159, SEQ ID NO 162, and SEQ ID NOs 164-172, SEQ ID NOs 176-178, SEQ ID NOs 181-196, and SEQ ID NOs 203-314. [00291 In one embodiment, the present invention provides an aptamer that binds to human IL-23 comprising a nucleic acid sequence at least 80% identical, more preferably at least 90% identical to any one of the sequences selected from the group consisting of: SEQ ID NOs 13-66, SEQ ID NOs 71-88, SEQ ID NOs 91-96, SEQ ID NOs 103-118, SEQ ID NOs 124-130, SEQ ID NOs 135-159, SEQ ID NO 162, and SEQ ID NOs 164-172, SEQ ID NOs 176-178, SEQ ID NOs 181-196, and SEQ ID NOs 203-314. In another embodiment, the present invention provides an aptamer comprising 4 contiguous nucleotides, preferably 8 contiguous nucleotides, more preferably 20 contiguous nucleotides that are identical to a sequence of 4, 8, or 20 contiguous nucleotides in the unique sequence region of any one of the sequences selected from the group of: SEQ ID NOs 13-66, SEQ ID NOs 71-88, SEQ ID NOs 91-96, SEQ ID NOs 103-118, SEQ ID NOs 124-130, SEQ ID NOs 135-159, SEQ ID NO 162, and SEQ ID NOs 164-172, SEQ ID NOs 176-178, SEQ ID NOs 181-196, and SEQ ID NOs 203-314. In yet another embodiment the present invention provides an aptamer capable of binding human IL-23 or a variant thereof comprising a nucleotide sequence selected from the group consisting of: SEQ ID NOs 13-66, SEQ ID NOs 71-88, SEQ ID NOs 91-96, SEQ ID NOs 103-118, SEQ ID NOs 124-130, SEQ ID NOs 135-159, SEQ ID NO 162, and SEQ ID NOs 164-172, SEQ ID NOs 176-178, SEQ ID NOs 181-196, and SEQ ID NOs 203-314. In another embodiment, the present invention provides an aptamer having the sequence set forth in SEQ ID NO 177, preferably SEQ ID NO 224, more preferably SEQ ID NO 309, more preferably SEQ ID NO 310, and more preferably SEQ ID NO 311. [0030] In one embodiment, the present invention provides aptamers that specifically bind to mouse IL-23. In another embodiment, the present invention provides aptamers that bind to a variant of mouse IL-23 that performs a biological function that is essentially the same as a function of mouse IL-23 and has substantially the same structure and substantially the same ability to bind said aptamer as that of mouse IL-23. [0031] In one embodiment, mouse IL-23 or a variant thereof to which the aptamer of the invention binds comprises an amino acid sequence which is at least 80%, preferably at least 90% identical to a sequence comprising SEQ ID NOs 321 and/or 322. In another 9 WO 2007/035922 PCT/US2006/037276 embodiment mouse IL-23 or a variant thereof has an amino acid sequence comprising SEQ ID NOs 321 and 322. [0032] In one embodiment, the aptamer of the invention has a dissociation constant for mouse IL-23 or a variant thereof of about 100 nM or less, preferably 50 nM or less, more preferably 10 nM or less. [0033] In one embodiment, the aptamer of the invention modulates a function of mouse IL-23 or a variant thereof. In one embodiment, the aptamer of the invention stimulates a function of mouse IL-23. In another embodiment, the aptamer of the invention inhibits a function of mouse IL-23 or a variant thereof. In yet another embodiment, the aptamer of the invention inhibits a function of mouse IL-23 or a variant thereof in vivo. In yet another embodiment, the aptamer of the invention prevents the binding of mouse IL-23 to the mouse IL-23 receptor. In some embodiments, the function of mouse IL-23 which is modulated by the aptamer of the present invention is to mediate a disease model associated with mouse IL-23 such as experimental autoimmune encephalomyelitis, murine collagen-induced arthritis, and TNBS colitis. [00341 In one embodiment, the aptamer of the invention has substantially the same ability to bind mouse IL-23 as that of an aptamer comprising a nucleotide sequence selected from the group consisting of SEQ ID NOs 124-134 and SEQ ID NOs 199-202. In another embodiment, the aptamer of the invention has substantially the same structure and substantially the same ability to bind mouse IL-23 as that of an aptamer comprising a nucleotide sequence selected from the group consisting of SEQ ID NOs 124-134 and SEQ ID NOs 199-202. [00351 In one embodiment, the present invention provides aptamers that bind to mouse IL-23 comprising a nucleic acid sequence at least 80% identical, preferably at least 90% identical to any one of the sequences selected from the group consisting of SEQ ID NOs 124-134, and SEQ ID NOs 199-202. In another embodiment, the present invention provides aptamers comprising 4 contiguous, preferably 8 contiguous, more preferably 20 contiguous nucleotides that are identical to a sequence of 4, 8 or 20 contiguous nucleotides in the unique sequence region of any one of the sequences selected from the group consisting of: SEQ ID NOs 124-134 and SEQ ID NOs 199-202. In another embodiment, the present invention provides an aptamer capable of binding mouse IL-23 or a variant thereof 10 WO 2007/035922 PCT/US2006/037276 comprising a nucleotide sequence selected from the group consisting of: SEQ ID NOs 124 134 and SEQ ID NOs 199-202. [0036] In one embodiment, the materials of the present invention provide aptamers that specifically bind to IL- 12. In one embodiment, IL- 12 to which the aptamers of the invention bind is human IL-12 while in another embodiment IL-12 is a variant of human IL-12. In one embodiment the variant of IL- 12 performs a biological function that is essentially the same as a function of human IL-12 and has substantially the same structure and substantially the same ability to bind said aptamer as that of human IL-12. [00371 In one embodiment, human IL-12 or a variant thereof comprises an amino acid sequence which is at least 80% identical, preferably at least 90% identical to a sequence comprising SEQ ID NOs 4 and/or 6. In another embodiment, human IL-12 or a variant thereof has an amino acid sequence comprising SEQ ID NOs 4 and 6. [00381 In one embodiment, the aptamer of the present invention modulates a function of human IL-12 or a variant thereof. In one embodiment, the aptaner of the present invention stimulates a function of human IL-23. In another embodiment, the aptamer of the present invention inhibits a function of human IL- 12 or a variant thereof. In yet another embodiment, the aptamer of the present invention inhibits a function of human IL-12 or a variant thereof in vivo. In yet another embodiment, the aptamer of the present invention prevents IL- 12 from binding to the IL- 12 receptor. In one embodiment, the function of human IL- 12 or a variant thereof which is modulated by the aptamer of the invention is to mediate a disease associated with human IL- 12 such as: autoimmune disease (including but not limited to multiple sclerosis, rheumatoid arthritis, psoriasis, systemic lupus erythamatosus, and irritable bowel disease (e.g., Crohn's Disease and ulcerative colitis)), inflammatory disease, cancer (including but not limited to colon cancer, lung cancer, and lung metastases), bone resorption in osteoporosis, and Type I Diabetes. [0039] In one embodiment, the present invention provides aptamers which are either ribonucleic or deoxyribonucleic acid. In a further embodiment, these ribonucleic or deoxyribonucleic acid aptamers are single stranded. In another embodiment, the present invention provides aptamers comprising at least one chemical modification. In one embodiment, the modification is selected from the group consisting of: a chemical substitution at a sugar position; a chemical substitution at a phosphate position; and a chemical substitution at a base position, of the nucleic acid; incorporation of a modified 11 WO 2007/035922 PCT/US2006/037276 nucleotide; 3' capping; conjugation to a high molecular weight, non-immunogenic compound; conjugation to a lipophilic compound; and phosphate backbone modification. In one embodiment, the non-immunogenic, high molecular weight compound conjugated to the aptamer of the invention is polyalkylene glycol, preferably polyethylene glycol. In one, embodiment, the backbone modification comprises incorporation of one or more phosphorothioates into the phosphate backbone. In another embodiment, the aptamer of the invention comprises the incorporation of fewer than 10, fewer than 6, or fewer than 3 phosphorothioates in the phosphate backbone. [00401 In one embodiment, the materials of the present invention provide a pharmaceutical composition comprising a therapeutically effective amount of an aptamer comprising a nucleic acid sequence selected from the group consisting of: SEQ ID NOs 13 66, SEQ ID NOs 71-88, SEQ ID NOs 91-96, SEQ ID NOs 103-118, SEQ ID NOs 124-130, SEQ ID NOs 135-159, SEQ ID NO 162, and SEQ ID NOs 164-172, SEQ ID NOs 176-178, SEQ ID NOs 181-196, and SEQ ID NOs 203-314, or a salt thereof, and a pharmaceutically acceptable carrier or diluent. In another embodiment, the materials of the present invention provide a pharmaceutical composition comprising a therapeutically effective amount of an aptamer comprising a nucleic acid sequence selected from the group consisting of: SEQ ID NO 14, SEQ ID NOs 17-19, SEQ ID NO 21, SEQ ID NOs 27-32, SEQ ID NOs 34-40, SEQ ID NO 42, SEQ ID NO 49, SEQ ID NOs 60-61, SEQ ID NOs 91-92, SEQ ID NO 94, and SEQ ID NOs 103-118, or a salt thereof, and a pharmaceutically acceptable carrier or diluent. In a preferred embodiment, the materials of the present invention provide a pharmaceutical composition comprising a therapeutically effective amount of an aptamer comprising a nucleic acid sequence selected from the group consisting of: SEQ ID NO 177, SEQ ID NO 224, and SEQ ID NOs 309-312. [0041] In one embodiment, the present invention provides a method of treating, preventing or ameliorating a disease mediated by IL-23, comprising administering the composition comprising a therapeutically effective amount of an aptamer comprising a nucleic acid sequence selected from the group consisting of: SEQ ID NOs 13-66, SEQ ID NOs 71-88, SEQ ID NOs 91-96, SEQ ID NOs 103-118, SEQ ID NOs 124-130, SEQ ID NOs 135-159, SEQ ID NO 162, and SEQ ID NOs 164-172, SEQ ID NOs 176-178, SEQ ID NOs 181-196, and SEQ ID NOs 203-314, to a vertebrate. In another embodiment, the present invention provides a method of treating, preventing or ameliorating a disease mediated by IL-23 and/or IL-12, comprising administering the composition comprising a 12 WO 2007/035922 PCT/US2006/037276 therapeutically effective amount of an aptamer comprising a nucleic acid sequence selected from the group consisting of: SEQ ID NO 14, SEQ ID NOs 17-19, SEQ ID NO 21, SEQ ID NOs 27-32, SEQ ID NOs 34-40, SEQ ID NO 42, SEQ ID NO 49, SEQ ID NOs 60-61, SEQ ID NOs 91-92, SEQ ID NO 94, and SEQ ID NOs 103-118, to a vertebrate. In a preferred embodiment the composition comprising a therapeutically effective amount of an aptamer administered to a vertebrate comprises a nucleic acid sequence selected from the group consisting of: SEQ ID NO 177, SEQ ID NO 224, and SEQ ID NOs 309-312. In one embodiment the vertebrate to which the pharmaceutical composition is administered is a mammal. In a preferred embodiment, the mammal is a human. [0042] In one embodiment, the disease treated, prevented or ameliorated by the methods of the present invention is selected from the group consisting of: autoimmune disease (including but not limited to multiple sclerosis, rheumatoid arthritis, psoriasis, systemic lupus erythamatosus, and irritable bowel disease (e.g., Crohn's Disease and ulcerative colitis)), inflammatory disease, cancer (including but not limited to colon cancer, lung cancer, and lung metastases), bone resorption in osteoporosis, and Type I Diabetes. [0043] In one embodiment, the present invention provides a diagnostic method comprising contacting an aptamer with a nucleic acid sequence selected from the group consisting of: SEQ ID NOs 13-66, SEQ ID NOs 71-88, SEQ ID NOs 91-96, SEQ ID NOs 103-118, SEQ ID NOs 124-134, SEQ ID NOs 135-159, SEQ ID NO 162, and SEQ ID NOs 164-172, SEQ ID NOs 176-178, SEQ ID NOs 181-196, and SEQ ID NOs 199-314 with a composition suspected of comprising IL-23 and/or IL- 12 or a variant thereof, and detecting the presence or absence of IL-23 and/or IL- 12 or a variant thereof. [00441 In one embodiment, the present invention provides an aptainer with a nucleic acid sequence selected from the group consisting of: SEQ ID NOs 13-66, SEQ ID NOs 71 88, SEQ ID NOs 91-96, SEQ ID NOs 103-118, SEQ ID NOs 124-134, SEQ ID NOs 135 159, SEQ ID NO 162, and SEQ ID NOs 164-172, SEQ ID NOs 176-178, SEQ ID NOs 181 196, and SEQ ID NOs 199-314 for use as an in vitro diagnostic. In another embodiment, the present invention provides an aptamer with a nucleic acid sequence selected from the group consisting of: SEQ ID NOs 13-66, SEQ ID NOs 71-88, SEQ ID NOs 91-96, SEQ ID NOs 103-118, SEQ ID NOs 124-134, SEQ ID NOs 135-159, SEQ ID NO 162, and SEQ ID NOs 164-172, SEQ ID NOs 176-178, SEQ ID NOs 181-196, and SEQ ID NOs 199-314 for use as an in vivo diagnostic. In yet another embodiment, the present invention provides an 13 WO 2007/035922 PCT/US2006/037276 aptamer with a nucleic acid sequence selected from the group consisting of: SEQ ID NOs 13-66, SEQ ID NOs 71-88, SEQ ID NOs 91-96, SEQ ID NOs 103-118, SEQ ID NOs 124 134, SEQ ID NOs 135-159, SEQ ID NO 162, and SEQ ID NOs 164-172, SEQ ID NOs 176 178, SEQ ID NOs 181-196, and SEQ ID NOs 199-314 for use in the treatment, prevention or amelioration of disease in vivo. [00451 In another embodiment, an aptamer is provided that binds to IL-23, wherein the aptamer inhibits IL-23 induced STAT 3 phosphorylation and the aptamer is SEQ ID NO: 309 or an aptamer that has the same ability to inhibit IL-23 induced STAT 3 phosphorylation as SEQ ID NO: 309 and wherein the aptamer comprises a KD less than 100nM. In some embodiments the aptamer of this aspect of the invention comprises a KD less than 500 nM and in some embodiments less than 50 nM. In some embodiments of this aspect of the invention, the aptamer aptamer inhibits IL-23 induced STAT 3 phosphorylation in vitro. In some embodiments, the aptamer inhibition of IL-23 induced STAT 3 phosphorylation is measured in lysates of peripheral blood mononuclear cells while in other embodiments inhibition is measured in PHA Blasts. In some embodiments, the aptamer having the same ability to inhibit IL-23 induced STAT 3 phosphorylation is selected from the group consisting of: SEQ ID NOS: 306 to 308 and 310 to 314. In some embodiments, the aptamer binds human IL-23. [00461 In some embodiments he aptaner of this aspect of the invention is further modified to comprise at least one chemical modification. In some embodiments the chemical modification is selected from the group consisting: of a chemical substitution at a sugar position; a chemical substitution at a phosphate position; and a chemical substitution at a base position, of the nucleic acid. In some embodiments, the modification is selected from the group consisting of: incorporation of a modified nucleotide, 3' capping, conjugation to a high molecular weight, non-immunogenic compound, and conjugation to a lipophilic compound. In a particular embodiment, the non-immunogenic, high molecular weight compound is polyalkylene glycol, preferably polyethylene glycol. [0047] In a particular embodiment, the aptamer provided by the invention binds to IL 23 and comprises an aptamer nucleic acid sequence that is at least 95 % identical to primary sequence according to SEQ ID NO: 309. In some embodiments, the the aptamer provided by the inventon binds to IL-23 and comprises an aptamer nucleic acid sequence that is at least 95 % identical to sequence SEQ ID NO: 309 including chemical modifications 14 WO 2007/035922 PCT/US2006/037276 wherein the percent homology is determined by visual inspection and the percent identity is calculated as the percentage nucleotides found in the smaller of two sequences which align with identical nucleotide residues, including chemical modifications, in the sequence being compared when 1 gap in a length of ten nucleotides may be introduced to assist in that alignment. In a particular embodiment, an aptamer comprising the nucleic acid sequence set forth in SEQ ID NO: 309 is provided. [0048] In a particular embodiment, an aptamer comprising the nucleic acid sequence set forth in SEQ ID NO: 309 is provided. In another embodiment of this aspect of the invention, an aptamer comprising a nucleic acid sequence selected from the group consisting of SEQ ID NOS 306 to 308 and SEQ ID NO: 310 to 314 is provided. In some embodiments the aptamer of this aspect further comprises a PEG, particularly a PEG comprising a molecular weight selected from the group consisting of : 20 and 40 kDA. [0049] In a particular embodiment an aptamer having the structure set forth below is provided: 0 ii H O-C-Nona-5' Aptamer 3' 20 kDa mPEG-O 20 kDa mPEG wherein: indicates a linker and the Aptamer is selected from the group consisting of SEQ ID NOS 306 to 311 and SEQ ID NO 314. . In a particular embodiment of this aspect, the Aptamer = dAmCdAdGdGmCdAdAdGmUdAdAm UmUdGmGmG-s-dG-s-dA-s-dGmU-s dGmCmGmGdGnCdGdGmGmGmUdGmU-3T (SEQ ID NO: 309) wherein "d" indicates a 2' deoxy nucleotide, "m" indicates a 2'-Ome nucleotide, s indicates a phosphorothioate substitution at a non-bridging phosphate position and 3T indicates an inverted deoxy thymidine. In some embodiments, the linker is an alkyl linker, particularly an alkyl linker comprising 2 to 18 consecutive CH 2 groups, more particularly an alkyl linker comprises 2 to 12 consecutive CH 2 groups, more particularly an alkyl linker comprising 3 to 6 consecutive CH 2 groups. 15 WO 2007/035922 PCT/US2006/037276 In one embodiment, an aptamer is provided having the structure set forth below: 0 0 0-C-N P 20 kDa mPEG-0 H - 0-5' Aptamer 3' 20 kDa mPEG-0 wherein the Aptamer is selected from the group consisting of of SEQ ID NOS 306 to 311 and SEQ ID NO 314. In a particular embodiment of this aspect, the Aptamer dAnCdAdGdGmCdAdAdGmUdAdAnUnUdGnGmG-s-dG-s-dA-s-dGmU-s dGmCmGmGdGmCdGdGmGmGmUdGnU-3T (SEQ ID NO: 309) wherein "d" indicates a 2' deoxy nucleotide, "m" indicates a 2'-Ome nucleotide, s indicates a phosphorothioate substitution at a non-bridging phosphate position and 3T indicates an inverted deoxy thymidine. In another embodiment, an aptamer comprising the following structure is provided: 0 0 11 H 20 kDa mPEG-0-C-N,^~~ 5' Aptamer 3' ^N-C---20 kDa mPEG H where: indicates a linker and the Aptamer is selected from the group consisting of SEQ ID NOS 306 to 311 and SEQ ID NO 314 except that the Aptamer is lacking the 3' 3T. In a particular embodiment of this aspect, the Aptamer = dAmCdAdGdGmCdAdAdGmUdAdAmUmUdGmGmG-s-dG-s-dA-s-dGmU-s dGmCmGmGdGmCdGdGmGmGmUdGmU wherein "d" indicates a 2' deoxy nucleotide, "i" indicates a 2'-Ome nucleotide, s indicates a phosphorothioate substitution at a non-bridging phosphate position. In some embodiments, the linker is an alkyl linker, particularly an alkyl linker comprising 2 to 18 consecutive CH 2 groups, more particularly an alkyl linker comprises 2 to 12 consecutive CH 2 groups, more particularly an alkyl linker comprising 3 to 6 consecutive C-1 2 groups. In a particular embodiment, an aptamer comprising the following structure is provided: 0 0 0 0 20 kDa mPEG-O-C-N O O - N-C-0-20 kDa mPEG H - O-5'Aptamer 3'-O'\O H 16 WO 2007/035922 PCT/US2006/037276 wherein the Aptamer is selected from the group consisting of SEQ ID NOS 306 to 311 and SEQ ID NO 314 except that the Aptamer is lacking the 3' 3T. In a particular embodiment of this aspect, the Aptamer = dAmCdAdGdGmCdAdAdGnUdAdAmUnUdGmGmG-s dG-s-dA-s-dGmU-s-dGmCrmGmGdGmCdGdGnGmGmUdGnU wherein "d" indicates a 2' deoxy nucleotide, "m" indicates a 2'-Ome nucleotide, s indicates a phosphorothioate substitution at a non-bridging phosphate position. In another aspect, the invention provices a composition comprising a therapeutically effective amount of an aptamer of the invention or a salt thereof and a phannaceutically acceptable carrier or diluent. In another aspect, the invention provides a method of treating, preventing or ameliorating a disease mediated by 11-23 comprising administering the aptamer of the invention to a patient in need thereof.. In yet another aspect of the invention, a diagnostic method comprising contacting an aptamer of the invention with a test composition and detecting the presence or absence of IL-23, is provided. BRIEF DESCRIPTION OF THE DRAWINGS [0050] Figure 1 is a schematic representation of the Interleukin-12 family of cytokines. [0051] Figure 2 is a schematic representation of the in vitro aptamer selection

(SELEX

m ) process from pools of random sequence oligonucleotides. [00521 Figure 3 is a schematic of the in vitro selection scheme for selecting aptamers specific to IL-23 by including IL-12 in the negative selection step thereby eliminating sequences that recognize p40, the common subunit in both IL-12 and IL-23. [00531 Figure 4 is an illustration of a 40 kDa branched PEG. [0054] Figure 5 is an illustration of a 40 kDa branched PEG attached to the 5'end of an aptamer. [0055] Figure 6 is an illustration depicting various PEGylation strategies representing standard mono-PEGylation, multiple PEGylation, and dimerization via PEGylation. [0056] Figure 7 is a graph showing binding of rRmY and rGmH pools to IL-23 after various rounds of selection. 17 WO 2007/035922 PCT/US2006/037276 [0057] Figure 8A is a representative schematic of the sequence and predicted secondary structure configuration of a Type 1 IL-23 aptamers; Figure 8B is a representative schematic of the sequences and predicted secondary structure configuration of several Type 2 IL-23 aptamers. [0058] Figure 9A is a schematic of the minimized aptamer sequences and predicted secondary structure configurations for Type 1 IL-23 aptamers; Figure 9B is a schematic of the minimized aptamer sequences and predicted secondary structure configurations for Type 2 IL-23 aptamers. [0059] Figure 10 depicts the predicted G-Quartet structure for dRmY minimer ARC979 (SEQ ID NO 177). [0060] Figure 11 is a graph showing an increase of NMM fluorescence in ARC979 (SEQ ID NO 177), confining that ARC979 adopts a G-quartet structure. [0061] Figure 12 is a graph of the ARC979 (SEQ ID NO 177) competition binding curve analyzed based on total [aptamer] bound using 50 nM IL-23. [0062] Figure 13 is a graph of the ARC979 (SEQ ID NO 177) competition binding curve analyzed based on [aptamer] bound using 250 nM IL-12. [00631 Figure 14 is a graph of the direct binding curves for ARC979 (SEQ ID NO 177) under two different binding reaction conditions (1X PBS (without Ca++ or Mg**) or 1X Dulbeccos PBS (with Ca** and Mg++). [0064] Figure 15 is a graph of the direct binding curves for ARC979 (SEQ ID NO 177) phosphorothioate derivatives depicting that single phosphorothioate substitutions yield increased proportion binding to IL-23. [0065] Figure 16 is a graph of the competition binding curves for ARC979 (SEQ ID NO 177) phosphorothioate derivatives depicting that single phosphorothioate substitutions compete for IL-23 at a higher affinity that ARC979. [0066] Figure 17 is a graph of the direct binding curves for the ARC979 optimized derivatives ARC 1624 (SEQ ID NO 310) and ARC 1625 (SEQ ID NO 311), compared to the parent ARC979 (SEQ ID NO 177) aptamer (ARC895 is a negative control). [0067] Figure 18 is a graph depicting the plasma stability of ARC979 (SEQ ID NO 177) compared to optimized ARC979 derivative constructs. 18 WO 2007/035922 PCT/US2006/037276 [00681 Figure 19 is a schematic representation of the TransAlM\ assay used to measure STAT3 activity in lysates of PHA blast cells exposed to aptamers of the invention. [0069] Figure 20 is a flow diagram of the protocol used for the detection of IL-23 induced STAT3 phosphorylation in PHA blasts exposed to aptamers of the invention. [0070] Figure 21 is a representative graph showing the inhibitory effect of parental IL 23 aptamers of rRfY composition compared to their respective optimized clones on IL-23 induced STAT3 phosphorylation in PHA Blasts using the TransAM m Assay. [00711 Figure 22 is a graph of the percent inhibition of IL-23 induced STAT3 phosphorylation by IL-23 aptamers of dRmY composition in the TransAM " assay (ARC793 (SEQ ID NO 163) is a non-binding aptamer). [0072] Figure 23 is a graph of the percent inhibition of IL-23 induced STAT3 phosphorylation by parental IL-23 aptamers of dRmY composition (ARC621 (SEQ ID NO 108), ARC627 (SEQ ID NO 110)) compared to their respective optimized clones (ARC979 (SEQ ID NO 177), ARC980 (SEQ ID NO 178), ARC982 (SEQ ID NO 180)) in the TransAM assay. [00731 Figure 24 is a percent inhibition graph of IL-23 induced STAT 3 phosphorylation by ARC979 (SEQ ID NO 177) and two optimized derivative clones of ARC979 (ARC 1624 (SEQ ID NO 310) and ARC 1625 (SEQ ID N03 11)) in the Pathscan* assay. [00741 Figure 25 is a graph comparing human and mouse IL-23 induced STAT3 activation in human PHA Blasts, measured by the TransAM m assay. [0075] Figure 26A is a schematic of one PEGylation strategy of anti-IL-23 aptamers where a 40 kDa branched PEG is conjugated to the 5' end of an aptamer via a linker. Figure 26B is a schematic of an anti-IL-23 aptamer with a 40 kDa branched PEG conjugated to the 5' end via an alkyl linker containing 6 consecutive CH 2 groups. [0076] Figure 27A is a schematic of one PEGylation strategy for anti-IL-23 aptamers, where a 20 kDa PEG is conjugated to both the 5' and 3' ends of the aptamer via a linker. Figure 27B is a schematic of an anti-IL-23 aptamer with a 20 kDa PEG conjugated to both the 5' and 3' ends of the aptaner via an alkyl linker containing 6 consecutive CH 2 groups. [00771 Figure 28 is graph of the percent inhibition of IL-23 induced STAT 3 phosphorylation by ARC1988 (SEQ ID NO 317) compared to ARC1623 (SEQ ID NO 309) 19 WO 2007/035922 PCT/US2006/037276 in the Pathscan* assay. The "control" is a non-specific irrelevant aptamer used as a negative control in the assay. [0078] Figure 29 is a bar graph comparing the inhibition of IL-23/IL-2 induced IL- 17 production in mouse splenocytes by anti-IL-23 aptamers ARC 1623 (SEQ ID NO 317), ARC 1623 (SEQ ID NO 309). The "minus IL-23" label on the X-axis denotes a control, mouse splenocytes treated without IL-23 (IL-2 only), the "plus IL-23" label on the X-axis denotes a control, mouse splenocytes treated with IL-2 and IL-23 alone, "p40 Mab" label in the legend denotes a human p40 antibody used to treat mouse splenocytes induced with IL 23/IL-2, used as a positive control for the aptamers, "irr ab" in the legend denotes an irrelevant antibody used as the negative control for the human p40 antibody, and corresponds to the "Ab control" label on the X-axis, and "irr apt" in the legend denotes a non-specific aptamer used as a negative control for the anti-IL-23 aptamers. [0079] Figure 30 is a graph comparing the percent inhibition of IL-23/IL-18 and IL 12/IL-18 induced Interferon-gamma production in PHA Blasts by the anti-IL-23 aptamer ARC1988 (SEQ ID NO 317). DETAILED DESCRIPTION OF THE INVENTION [0080] The details of one or more embodiments of the invention are set forth in the accompanying description below. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. Other features, objects, and advantages of the invention will be apparent from the description. In the specification, the singular forms also include the plural unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In the case of conflict, the present Specification will control. THE SELEX" METHOD [0081] A suitable method for generating an aptamer is with the process entitled "Systematic Evolution of Ligands by Exponential Enrichment" ("SELEXTM") generally depicted in Figure 2. The SELEXTM process is a method for the in vitro evolution of nucleic acid molecules with highly specific binding to target molecules and is described in, 20 WO 2007/035922 PCT/US2006/037276 e.g., U.S. patent application Ser. No. 07/536,428, filed Jun. 11, 1990, now abandoned, U.S. Pat. No. 5,475,096 entitled "Nucleic Acid Ligands", and U.S. Pat. No. 5,270,163 (see also WO 91/19813) entitled "Nucleic Acid Ligands". Each SELEX""-identified nucleic acid ligand, i.e., each aptamer, is a specific ligand of a given target compound or molecule. The SELEX process is based on the unique insight that nucleic acids have sufficient capacity for forming a variety of two- and three-dimensional structures and sufficient chemical versatility available within their monomers to act as ligands (i.e., forn specific binding pairs) with virtually any chemical compound, whether monomeric or polymeric. Molecules of any size or composition can serve as targets. [0082] SELEX7 relies as a starting point upon a large library or pool of single stranded oligonucleotides comprising randomized sequences. The oligonucleotides can be modified or unmodified DNA, RNA, or DNA/RNA hybrids. In some examples, the pool comprises 100% random or partially random oligonucleotides. In other examples, the pool comprises random or partially random oligonucleotides containing at least one fixed sequence and/or conserved sequence incorporated within randomized sequence. In other examples, the pool comprises random or partially random oligonucleotides containing at least one fixed sequence and/or conserved sequence at its 5' and/or 3' end which may comprise a sequence shared by all the molecules of the oligonucleotide pool. Fixed sequences are sequences common to oligonucleotides in the pool which are incorporated for a preselected purpose such as, CpG motifs described further below, hybridization sites for PCR primers, promoter sequences for RNA polymerases (e.g., T3, T4, T7, and SP6), restriction sites, or homopolymeric sequences, such as poly A or poly T tracts, catalytic cores, sites for selective binding to affinity columns, and other sequences to facilitate cloning and/or sequencing of an oligonucleotide of interest. Conserved sequences are sequences, other than the previously described fixed sequences, shared by a number of aptamers that bind to the same target. [0083] The oligonucleotides of the pool preferably include a randomized sequence portion as well as fixed sequences necessary for efficient amplification. Typically the oligonucleotides of the starting pool contain fixed 5' and 3' terminal sequences which flank an internal region of 30-50 random nucleotides. The randomized nucleotides can be produced in a number of ways including chemical synthesis and size selection from randomly cleaved cellular nucleic acids. Sequence variation in test nucleic acids can also be 21 WO 2007/035922 PCT/US2006/037276 introduced or increased by mutagenesis before or during the selection/amplification iterations. [00841 The random sequence portion of the oligonucleotide can be of any length and can comprise ribonucleotides and/or deoxyribonucleotides and can include modified or non natural nucleotides or nucleotide analogs. See, e.g., U.S. Patent No. 5,958,691; U.S. Patent No. 5,660,985; U.S. Patent No. 5,958,691; U.S. Patent No. 5,698,687; U.S. Patent No. 5,817,635; U.S. Patent No. 5,672,695, and PCT Publication WO 92/07065. Random oligonucleotides can be synthesized from phosphodiester-linked nucleotides using solid phase oligonucleotide synthesis techniques well known in the art. See, e.g., Froehler et al., Nucl. Acid Res. 14:5399-5467 (1986) and Froehler et al., Tet. Lett. 27:5575-5578 (1986). Random oligonucleotides can also be synthesized using solution phase methods such as triester synthesis methods. See, e.g., Sood et al., Nucl. Acid Res. 4:2557 (1977) and Hirose et al., Tet. Lett., 28:2449 (1978). Typical syntheses carried out on automated DNA synthesis equipment yield 1014-1016 individual molecules, a number sufficient for most SELEX" experiments. Sufficiently large regions of random sequence in the sequence design increases the likelihood that each synthesized molecule is likely to represent a unique sequence. [0085] The starting library of oligonucleotides may be generated by automated chemical synthesis on a DNA synthesizer. To synthesize randomized sequences, mixtures of all four nucleotides are added at each nucleotide addition step during the synthesis process, allowing for random incorporation of nucleotides. As stated above, in one embodiment, random oligonucleotides comprise entirely random sequences; however, in other embodiments, random oligonucleotides can comprise stretches of nonrandom or partially random sequences. Partially random sequences can be created by adding the four nucleotides in different molar ratios at each addition step. [00861 The starting library of oligonucleotides may be either RNA or DNA. In those instances where an RNA library is to be used as the starting library it is typically generated by transcribing a DNA library in vitro using T7 RNA polymerase or modified T7 RNA polymerases and purified. The RNA or DNA library is then mixed with the target under conditions favorable for binding and subjected to step-wise iterations of binding, partitioning and amplification, using the same general selection scheme, to achieve virtually any desired criterion of binding affinity and selectivity. More specifically, starting with a 22 WO 2007/035922 PCT/US2006/037276 mixture containing the starting pool of nucleic acids, the SELEXIm method includes steps of: (a) contacting the mixture with the target under conditions favorable for binding; (b) partitioning unbound nucleic acids from those nucleic acids which have bound specifically to target molecules; (c) dissociating the nucleic acid-target complexes; (d) amplifying the nucleic acids dissociated from the nucleic acid-target complexes to yield a ligand-enriched mixture of nucleic acids; and (e) reiterating the steps of binding, partitioning, dissociating and amplifying tluough as many cycles as desired to yield highly specific, high affinity nucleic acid ligands to the target molecule. In those instances where RNA aptamers are being selected, the SELEX7 method further comprises the steps of: (i) reverse transcribing the nucleic acids dissociated from the nucleic acid-target complexes before amplification in step (d); and (ii) transcribing the amplified nucleic acids from step (d) before restarting the process. [00871 Within a nucleic acid mixture containing a large number of possible sequences and structures, there is a wide range of binding affinities for a given target. A nucleic acid mixture comprising, for example, a 20 nucleotide randomized segment can have 420 candidate possibilities. Those which have the higher affinity constants for the target are most likely to bind to the target. After partitioning, dissociation and amplification, a second nucleic acid mixture is generated, enriched for the higher binding affinity candidates. Additional rounds of selection progressively favor the best ligands until the resulting nucleic acid mixture is predominantly composed of only one or a few sequences. These can then be cloned, sequenced and individually tested for binding affinity as pure ligands or aptamers. [0088] Cycles of selection and amplification are repeated until a desired goal is achieved. In the most general case, selection/amplification is continued until no significant improvement in binding strength is achieved on repetition of the cycle. The method is typically used to sample approximately 1014 different nucleic acid species but may be used to sample as many as about 1018 different nucleic acid species. Generally, nucleic acid aptamer molecules are selected in a 5 to 20 cycle procedure. In one embodiment, heterogeneity is introduced only in the initial selection stages and does not occur throughout the replicating process. [0089] In one embodiment of SELEX" , the selection process is so efficient at isolating those nucleic acid ligands that bind most strongly to the selected target, that only one cycle 23 WO 2007/035922 PCT/US2006/037276 of selection and amplification is required. Such an efficient selection may occur, for example, in a chromatographic-type process wherein the ability of nucleic acids to associate with targets bound on a column operates in such a manner that the column is sufficiently able to allow separation and isolation of the highest affinity nucleic acid ligands. [0090] In many cases, it is not necessarily desirable to perform the iterative steps of SELEX " until a single nucleic acid ligand is identified. The target-specific nucleic acid ligand solution may include a family of nucleic acid structures or motifs that have a number of conserved sequences and a number of sequences which can be substituted or added without significantly affecting the affinity of the nucleic acid ligands to the target. By terminating the SELEXm process prior to completion, it is possible to determine the sequence of a number of members of the nucleic acid ligand solution family. [0091] A variety of nucleic acid primary, secondary and tertiary structures are known to exist. The structures or motifs that have been shown most commonly to be involved in non Watson-Crick type interactions are referred to as hairpin loops, symmetric and asymmetric bulges, pseudoknots and myriad combinations of the same. Almost all known cases of such motifs suggest that they can be formed in a nucleic acid sequence of no more than 30 nucleotides. For this reason, it is often preferred that SELEX7 procedures with contiguous randomized segments be initiated with nucleic acid sequences containing a randomized segment of between about 20 to about 50 nucleotides and in some embodiments, about 30 to about 40 nucleotides. In one example, the 5'-fixed:random:3'-fixed sequence comprises a random sequence of about 30 to about 50 nucleotides. [0092] The core SELEX method has been modified to achieve a number of specific objectives. For example, U.S. Patent No. 5,707,796 describes the use of SELEX7 in conjunction with gel electrophoresis to select nucleic acid molecules with specific structural characteristics, such as bent DNA. U.S. Patent No. 5,763,177 describes SELEX M based methods for selecting nucleic acid ligands containing photo reactive groups capable of binding and/or photo-crosslinking to and/or photo-inactivating a target molecule. U.S. Patent No. 5,567,588 and U.S. Patent No. 5,861,254 describe SELEX7 based methods which achieve highly efficient partitioning between oligonucleotides having high and low affinity for a target molecule. U.S. Patent No. 5,496,938 describes methods for obtaining improved nucleic acid ligands after the SELEXr process has been performed. U.S. Patent No. 5,705,337 describes methods for covalently linking a ligand to its target. 24 WO 2007/035922 PCT/US2006/037276 [00931 SELEX can also be used to obtain nucleic acid ligands that bind to more than one site on the target molecule, and to obtain nucleic acid ligands that include non-nucleic acid species that bind to specific sites on the target. SELEX" provides means for isolating and identifying nucleic acid ligands which bind to any envisionable target, including large and small biomolecules such as nucleic acid-binding proteins and proteins not known to bind nucleic acids as part of their biological function as well as cofactors and other small molecules. For example, U.S. Patent No. 5,580,737 discloses nucleic acid sequences identified through SELEXM which are capable of binding with high affinity to caffeine and the closely related analog, theophylline. [00941 Counter-SELEX is a method for improving the specificity of nucleic acid ligands to a target molecule by eliminating nucleic acid ligand sequences with cross reactivity to one or more non-target molecules. Counter- SELEX m is comprised of the steps of: (a) preparing a candidate mixture of nucleic acids; (b) contacting the candidate mixture with the target, wherein nucleic acids having an increased affinity to the target relative to the candidate mixture may be partitioned from the remainder of the candidate mixture; (c) partitioning the increased affinity nucleic acids from the remainder of the candidate mixture; (d) dissociating the increased affinity nucleic acids from the target; (e) contacting the increased affinity nucleic acids with one or more non-target molecules such that nucleic acid ligands with specific affinity for the non-target molecule(s) are removed; and (f) amplifying the nucleic acids with specific affinity only to the target molecule to yield a mixture of nucleic acids enriched for nucleic acid sequences with a relatively higher affinity and specificity for binding to the target molecule. As described above for SELEX

M

, cycles of selection and amplification are repeated as necessary until a desired goal is achieved. [00951 One potential problem encountered in the use of nucleic acids as therapeutics and vaccines is that oligonucleotides in their phosphodiester form may be quickly degraded in body fluids by intracellular and extracellular enzymes such as endonucleases and exonucleases before the desired effect is manifest. The SELEXi method thus encompasses the identification of high-affinity nucleic acid ligands containing modified nucleotides conferring improved characteristics on the ligand, such as improved in vivo stability or improved delivery characteristics. Examples of such modifications include chemical substitutions at the ribose and/or phosphate and/or base positions. SELEX 1 -identified nucleic acid ligands containing modified nucleotides are described, e.g., in U.S. Patent No. 5,660,985, which describes oligonucleotides containing nucleotide derivatives chemically 25 WO 2007/035922 PCT/US2006/037276 modified at the 2' position of ribose, 5 position of pyrimidines, and 8 position of purines, U.S. Patent No. 5,756,703 which describes oligonucleotides containing various 2'-modified pyrimidines, and U.S. Patent No. 5,580,737 which describes highly specific nucleic acid ligands containing one or more nucleotides modified with 2'-amino (2'-NH 2 ), 2'-fluoro (2' F), and/or 2'-0-methyl (2'-OMe) substituents. [0096] Modifications of the nucleic acid ligands contemplated in this invention include, but are not limited to, those which provide other chemical groups that incorporate additional charge, polarizability, hydrophobicity, hydrogen bonding, electrostatic interaction, and fluxionality to the nucleic acid ligand bases or to the nucleic acid ligand as a whole. Modifications to generate oligonucleotide populations which are resistant to nucleases can also include one or more substitute internucleotide linkages, altered sugars, altered bases, or combinations thereof. Such modifications. include, but are not limited to, 2'-position sugar modifications, 5-position pyrimidine modifications, 8-position purine modifications, modifications at exocyclic amines, substitution of 4-thiouridine, substitution of 5-bromo or 5-iodo-uracil; backbone modifications, phosphorothioate or alkyl phosphate modifications, methylations, and unusual base-pairing combinations such as the isobases isocytidine and isoguanosine. Modifications can also include 3' and 5' modifications such as capping. [0097] In one embodiment, oligonucleotides are provided in which the P(0)0 group is replaced by P(O)S ("thioate"), P(S)S ("dithioate"), P(O)NR 2 ("amidate"), P(O)R, P(O)OR', CO or CH 2 ("formacetal") or 3'-amine (-NH-CH 2

-CH

2 -), wherein each R or R' is independently H or substituted or unsubstituted alkyl. Linkage groups can be attached to adjacent nucleotides through an -0-, -N-, or -S- linkage. Not all linkages in the oligonucleotide are required to be identical. As used herein, the tern phosphorothioate encompasses one or more non-bridging oxygen atoms in a phosphodiester bond replaced by one or more sulfur atom. [0098] In further embodiments, the oligonucleotides comprise modified sugar groups, for example, one or more of the hydroxyl groups is replaced with halogen, aliphatic groups, or functionalized as ethers or amines. In one embodiment, the 2'-position of the furanose residue is substituted by any of an 0-methyl, 0-alkyl, 0-allyl, S-alkyl, S-allyl, or halo group. Methods of synthesis of 2'-modified sugars are described, e.g., in Sproat, et al., Nucl. Acid Res. 19:733-738 (1991); Cotten, et al., Nucl. Acid Res. 19:2629-2635 (1991); and Hobbs, et al., Biochemistry 12:5138-5145 (1973). Other modifications are known to 26 WO 2007/035922 PCT/US2006/037276 one of ordinary skill in the art. Such modifications may be pre-SELEX7 process modifications or post-SELEXM process modifications (modification of previously identified unmodified ligands) or may be made by incorporation into the SELEX' process. [00991 Pre- SELEX process modifications or those made by incorporation into the SELEX" process yield nucleic acid ligands with both specificity for their SELEXm target and improved stability, e.g., in vivo stability. Post-SELEX" process modifications made to nucleic acid ligands may result in improved stability, e.g., in vivo stability without adversely affecting the binding capacity of the nucleic acid ligand. [00100] The SELEX'" method encompasses combining selected oligonucleotides with other selected oligonucleotides and non-oligonucleotide functional units as described in U.S. Patent No. 5,637,459 and U.S. Patent No. 5,683,867. The SELEX M method further encompasses combining selected nucleic acid ligands with lipophilic or non-immunogenic high molecular weight compounds in a diagnostic or therapeutic complex, as described, e.g., in U.S. Patent No. 6,011,020, U.S. Patent No. 6,051,698, and PCT Publication No. WO 98/18480. These patents and applications teach the combination of a broad array of shapes and other properties, with the efficient amplification and replication properties of oligonucleotides, and with the desirable properties of other molecules. [00101] The identification of nucleic acid ligands to small, flexible peptides via the SELEXM method has also been explored. Small peptides have flexible structures and usually exist in solution in an equilibrium of multiple conformers, and thus it was initially thought that binding affinities may be limited by the confonnational entropy lost upon binding a flexible peptide. However, the feasibility of identifying nucleic acid ligands to small peptides in solution was demonstrated in U.S. Patent No. 5,648,214. In this patent, high affinity RNA nucleic acid ligands to substance P, an 11 amino acid peptide, were identified. [001021 The aptamers with specificity and binding affinity to the target(s) of the present invention are typically selected by the SELEX process as described herein. As part of the SELEX" process, the sequences selected to bind to the target are then optionally minimized to determine the minimal sequence having the desired binding affinity. The selected sequences and/or the minimized sequences are optionally optimized by performing random or directed mutagenesis of the sequence to increase binding affinity or alternatively to determine which positions in the sequence are essential for binding activity. Additionally, 27 WO 2007/035922 PCT/US2006/037276 selections can be performed with sequences incorporating modified nucleotides to stabilize the aptamer molecules against degradation in vivo. 2' MODIFIED SELEXTM [00103] In order for an aptamer to be suitable for use as a therapeutic, it is preferably inexpensive to synthesize, safe and stable in vivo. Wild-type RNA and DNA aptamers are typically not stable in vivo because of their susceptibility to degradation by nucleases. Resistance to nuclease degradation can be greatly increased by the incorporation of modifying groups at the 2'-position. [001041 Fluoro and amino groups have been successfully incorporated into oligonucleotide pools from which aptamers have been subsequently selected. However, these modifications greatly increase the cost of synthesis of the resultant aptamer, and may introduce safety concerns in some cases because of the possibility that the modified nucleotides could be recycled into host DNA by degradation of the modified oligonucleotides and subsequent use of the nucleotides as substrates for DNA synthesis. [001051 Aptamers that contain 2'-O-methyl ("2'-OMe") nucleotides, as provided herein, overcome many of these drawbacks. Oligonucleotides containing 2'-OMe nucleotides are nuclease-resistant and inexpensive to synthesize. Although 2'-OMe nucleotides are ubiquitous in biological systems, natural polyinerases do not accept 2'-OMe NTPs as substrates under physiological conditions, thus there are no safety concerns over the recycling of 2'-OMe nucleotides into host DNA. The SELEXTM method used to generate 2'-modified aptamers is described, e.g., in U.S. Provisional Patent Application Serial No. 60/430,761, filed December 3, 2002, U.S. Provisional Patent Application Serial No. 60/487,474, filed July 15, 2003, U.S. Provisional Patent Application Serial No. 60/517,039, filed November 4, 2003, U.S. Patent Application No. 10/729,581, filed December 3, 2003, and U.S. Patent Application No. 10/873,856, filed June 21, 2004, entitled "Method for in vitro Selection of 2'-O-methyl Substituted Nucleic Acids", each of which is herein incorporated by reference in its entirety. [001061 The present invention includes aptamers that bind to and modulate the function of IL-23 and/or IL-12 which contain modified nucleotides (e.g., nucleotides which have a modification at the 2' position) to make the oligonucleotide more stable than the unmodified oligonucleotide to enzymatic and chemical degradation as well as thermal and physical degradation. Although there are several examples of 2'-OMe containing aptamers in the 28 WO 2007/035922 PCT/US2006/037276 literature (see, e.g., Green et al., Current Biology 2, 683-695, 1995) these were generated by the in vitro selection of libraries of modified transcripts in which the C and U residues were 2'-fluoro (2'-F) substituted and the A and G residues were 2'-OH. Once functional sequences were identified then each A and G residue was tested for tolerance to 2'-OMe substitution, and the aptamer was re-synthesized having all A and G residues which tolerated 2'-OMe substitution as 2'-OMe residues. Most of the A and G residues of aptamers generated in this two-step fashion tolerate substitution with 2'-OMe residues, although, on average, approximately 20% do not. Consequently, aptamers generated using this method tend to contain from two to four 2'-OH residues, and stability and cost of synthesis are compromised as a result. By incorporating modified nucleotides into the transcription reaction which generate stabilized oligonucleotides used in oligonucleotide pools from which aptamers are selected and enriched by SELEX7 (and/or any of its variations and improvements, including those described herein), the methods of the present invention eliminate the need for stabilizing the selected aptamer oligonucleotides (e.g., by resynthesizing the aptamer oligonucleotides with modified nucleotides). [00107] In one embodiment, the present invention provides aptamers comprising combinations of 2'-OH, 2'-F, 2'-deoxy, and 2'-OMe modifications of the ATP, GTP, CTP, TTP, and UTP nucleotides. In another embodiment, the present invention provides aptamers comprising combinations of 2'-OH, 2'-F, 2'-deoxy, 2'-OMe, 2'-NH 2 , and 2' methoxyethyl modifications of the ATP, GTP, CTP, TTP, and UTP nucleotides. In another embodiment, the present invention provides aptamers comprising 56 combinations of 2' OH, 2'-F, 2'-deoxy, 2'-OMe, 2'-NH 2 , and 2'-methoxyethyl modifications of the ATP, GTP, CTP, TTP, and UTP nucleotides. [001081 2' modified aptamers of the invention are created using modified polymerases, e.g., a modified T7 polymerase, having a rate of incorporation of modified nucleotides having bulky substituents at the furanose 2' position that is higher than that of wild-type polymerases. For example, a single mutant T7 polymerase (Y639F) in which the tyrosine residue at position 639 has been changed to phenylalanine readily utilizes 2'deoxy, 2'amino-, and 2'fluoro- nucleotide triphosphates (NTPs) as substrates and has been widely used to synthesize modified RNAs for a variety of applications. However, this mutant T7 polymerase reportedly can not readily utilize (i.e., incorporate) NTPs with bulky 2' substituents such as 2'-OMe or 2'-azido (2'-N 3 ) substituents. For incorporation of bulky 2' substituents, a double T7 polymerase mutant (Y639F/H784A) having the histidine at 29 WO 2007/035922 PCT/US2006/037276 position 784 changed to an alanine residue in addition to the Y639F mutation has been described and has been used in limited circumstances to incorporate modified pyrimidine NTPs. See Padilla, R. and Sousa, R., Nucleic Acids Res., 2002, 30(24): 138. A single mutant T7 polymerase (H784A) having the histidine at position 784 changed to an alanine residue has also been described. Padilla et aL, Nucleic Acids Research, 2002, 30: 138. In both the Y639F/H784A double mutant and H784A single mutant T7 polymerases, the change to a smaller amino acid residue such as alanine allows for the incorporation of bulkier nucleotide substrates, e.g., 2'-OMe substituted nucleotides. [00109] Generally, it has been found that under the conditions disclosed herein, the Y693F single mutant can be used for the incorporation of all 2'-OMe substituted NTPs except GTP and the Y639F/H784A double mutant can be used for the incorporation of all 2'-OMe substituted NTPs including GTP. It is expected that the H784A single mutant possesses properties similar to the Y639F and the Y639F/H784A mutants when used under the conditions disclosed herein. [00110] 2'-modified oligonucleotides may be synthesized entirely of modified nucleotides, or with a subset of modified nucleotides. The modifications can be the same or different. All nucleotides may be modified, and all may contain the same modification. All nucleotides may be modified, but contain different modifications, e.g., all nucleotides containing the same base may have one type of modification, while nucleotides containing other bases may have different types of modification. All purine nucleotides may have one type of modification (or are unmodified), while all pyrimidine nucleotides have another, different type of modification (or are unmodified). In this way, transcripts, or pools of transcripts are generated using any combination of modifications, including for example, ribonucleotides (2'-OH), deoxyribonucleotides (2'-deoxy), 2'-F, and 2'-OMe nucleotides. A transcription mixture containing 2'-OMe C and U and 2'-OH A and G is referred to as an "rRmY" mixture and aptamers selected therefrom are referred to as "rRmnY" aptamers. A transcription mixture containing deoxy A and G and 2'-OMe U and C is referred to as a "dRmY" mixture and aptamers selected therefrom are referred to as "dRmY" aptaiers. A transcription mixture containing 2'-OMe A, C, and U, and 2'-OH G is referred to as a "rGmH" mixture and aptamers selected therefrom are referred to as "rGmH" aptamers. A transcription mixture alternately containing 2'-OMe A, C, U and G and 2'-OMe A, U and C and 2'-F G is referred to as an "alternating mixture" and aptamers selected therefrom are referred to as "alternating mixture" aptamers. A transcription mixture containing 2'-OMe 30 WO 2007/035922 PCT/US2006/037276 A, U, C, and G, where up to 10% of the G's are ribonucleotides is referred to as a "r/mGmH" mixture and aptamers selected therefrom are referred to as "r/mGmH" aptamers. A transcription mixture containing 2'-OMe A, U, and C, and 2'-F G is referred to as a "fGmH" mixture and aptamers selected therefrom are referred to as "fGmH" aptamers. A transcription mixture containing 2'-OMe A, U, and C, and deoxy G is referred to as a "dGmH" mixture and aptamers selected therefrom are referred to as "dGnH" aptamers. A transcription mixture containing deoxy A, and 2'-OMe C, G and U is referred to as a "dAmB" mixture and aptamers selected therefrom are referred to as "dArnB" aptamers, and a transcription mixture containing all 2'-OH nucleotides is referred to as a "rN" mixture and aptamers selected therefrom are referred to as "rN" or "rRrY" aptamers. A "mRmY" aptamer is one containing all 2'-O-methyl nucleotides and is usually derived from a r/mGmH oligonucleotide by post-SELEX replacement, when possible, of any 2'-OH Gs with 2'-OMe Gs. [00111] A preferred embodiment includes any combination of 2'-OH, 2'-deoxy and 2' OMe nucleotides. A more preferred embodiment includes any combination of 2'-deoxy and 2'-OMe nucleotides. An even more preferred embodiment is with any combination of 2' deoxy and 2'-OMe nucleotides in which the pyrimidines are 2'-OMe (such as dRmY, mRmY or dGmH). [00112] Incorporation of modified nucleotides into the aptamers of the invention is accomplished before (pre-) the selection process (e.g., a pre-SELEX" process modification). Optionally, aptamers of the invention in which modified nucleotides have been incorporated by pre-SELEX M process modification can be further modified by post SELEX'" process modification (i.e., a post-SELEX M process modification after a pre SELEX '1 modification). Pre-SELEX" process modifications yield modified nucleic acid ligands with specificity for the SELEX target and also improved in vivo stability. Post SELEXN process modifications, i.e., modification (e.g., truncation, deletion, substitution or additional nucleotide modifications of previously identified ligands having nucleotides incorporated by pre-SELEX7 process modification) can result in a further improvement of in vivo stability without adversely affecting the binding capacity of the nucleic acid ligand having nucleotides incorporated by pre-SELEX' process modification. [00113] To generate pools of 2'-modified (e.g., 2'-OMe) RNA transcripts in conditions under which a polymerase accepts 2'-modified NTPs the preferred polymerase is the 31 WO 2007/035922 PCT/US2006/037276 Y693F/H784A double mutant or the Y693F single mutant. Other polymerases, particularly those that exhibit a high tolerance for bulky 2'-substituents, may also be used in the present invention. Such polymerases can be screened for this capability by assaying their ability to incorporate modified nucleotides under the transcription conditions disclosed herein. [00114] A number of factors have been determined to be important for the transcription conditions useful in the methods disclosed herein. For example, increases in the yields of modified transcript are observed when a leader sequence is incorporated into the 5' end of a fixed sequence at the 5' end of the DNA transcription template, such that at least about the first 6 residues of the resultant transcript are all purines. [001151 Another important factor in obtaining transcripts incorporating modified nucleotides is the presence or concentration of 2'-OH GTP. Transcription can be divided into two phases: the first phase is initiation, during which an NTP is added to the 3' hydroxyl end of GTP (or another substituted guanosine) to yield a dinucleotide which is then extended by about 10-12 nucleotides; the second phase is elongation, during which transcription proceeds beyond the addition of the first about 10-12 nucleotides. It has been found that small amounts of 2'-OH GTP added to a transcription mixture containing an excess of 2'-OMe GTP are sufficient to enable the polymerase to initiate transcription using 2'-OH GTP, but once transcription enters the elongation phase the reduced discrimination between 2'-OMe and 2'-OH GTP, and the excess of 2'-OMe GTP over 2'-OH GTP allows the incorporation of principally the 2'-OMe GTP. [00116] Another important factor in the incorporation of 2'-OMe substituted nucleotides into transcripts is the use of both divalent magnesium and manganese in the transcription mixture. Different combinations of concentrations of magnesium chloride and manganese chloride have been found to affect yields of 2'-O-methylated transcripts, the optimum concentration of the magnesium and manganese chloride being dependent on the concentration in the transcription reaction mixture of NTPs which complex divalent metal ions. To obtain the greatest yields of maximally 2' substituted 0-methylated transcripts (i.e., all A, C, and U and about 90% of G nucleotides), concentrations of approximately 5 mM magnesium chloride and 1.5 mM manganese chloride are preferred when each NTP is present at a concentration of 0.5 mM. When the concentration of each NTP is 1.0 mM, concentrations of approximately 6.5 mM magnesium chloride and 2.0 mM manganese chloride are preferred. When the concentration of each NTP is 2.0 mM, concentrations of 32 WO 2007/035922 PCT/US2006/037276 approximately 9.6 mM magnesium chloride and 2.9 mM manganese chloride are preferred. In any case, departures from these concentrations of up to two-fold still give significant amounts of modified transcripts. [00117] Priming transcription with GMP or guanosine is also important. This effect results from the specificity of the polymerase for the initiating nucleotide. As a result, the 5'-terminal nucleotide of any transcript generated in this fashion is likely to be 2'-OH G. The preferred concentration of GMP (or guanosine) is 0.5 mM and even more preferably 1 mM. It has also been found that including PEG, preferably PEG-8000, in the transcription reaction is useful to maximize incorporation of modified nucleotides. [001181 For maximum incorporation of 2'-OMe ATP (100%), UTP (100%), CTP (100%) and GTP (~90%) ("r/mGmH") into transcripts the following conditions are preferred: HEPES buffer 200 mM, DTT 40 mM, spermidine 2 mM, PEG-8000 10% (w/v), Triton X 100 0.01% (w/v), MgCl 2 5 mM (6.5 mM where the concentration of each 2'-OMe NTP is 1.0 mM), MnCl 2 1.5 mM (2.0 mM where the concentration of each 2'-OMe NTP is 1.0 mM), 2'-OMe NTP (each) 500 pM (more preferably, 1.0 mM), 2'-OH GTP 30 pM, 2'-OH GMP 500 ptM, pH 7.5, Y639F/H784A T7 RNA Polymerase 15 units/mL, inorganic pyrophosphatase 5 units/mL, and an all-purine leader sequence of at least 8 nucleotides long. As used herein, one unit of the Y639F/H784A mutant T7 RNA polymerase (or any other mutant T7 RNA polymerase specified herein) is defined as the amount of enzyme required to incorporate 1 nmole of 2'-OMe NTPs into transcripts under the r/mGmH conditions. As used herein, one unit of inorganic pyrophosphatase is defined as the amount of enzyme that will liberate 1.0 mole of inorganic orthophosphate per minute at pH 7.2 and 25 0 C. [001191 For maximum incorporation (100%) of 2'-OMe ATP, UTP and CTP ("rGmH") into transcripts the following conditions are preferred: HEPES buffer 200 mM, DTT 40 mM, spermidine 2 mM, PEG-8000 10% (w/v), Triton X-100 0.0 1% (w/v), MgC1 2 5 mM (9.6 mM where the concentration of each 2'-OMe NTP is 2.0 mM), MnC1 2 1.5 mM (2.9 mM where the concentration of each 2'-OMe NTP is 2.0 mM), 2'-OMe NTP (each) 500 pM (more preferably, 2.0 mM), pH 7.5, Y639F T7 RNA Polymerase 15 units/mL, inorganic pyrophosphatase 5 units/mL, and an all-purine leader sequence of at least 8 nucleotides long. 33 WO 2007/035922 PCT/US2006/037276 [001201 For maximum incorporation (100%) of 2'-OMe UTP and CTP ("rRmY") into transcripts the following conditions are preferred: HEPES buffer 200 mM, DTT 40 mM, sperniidine 2 mM, PEG-8000 10% (w/v), Triton X-100 0.01% (w/v), MgCl 2 5 mM (9.6 mM where the concentration of each 2'-OMe NTP is 2.0 mM), MnCl 2 1.5 mM (2.9 mM where the concentration of each 2'-OMe NTP is 2.0 mM), 2'-OMe NTP (each) 500sM (more preferably, 2.0 mM), pH 7.5, Y639F/H784A T7 RNA Polymerase 15 units/mL, inorganic pyrophosphatase 5 units/mL, and an all-purine leader sequence of at least 8 nucleotides long. [00121] For maximum incorporation (100%) of deoxy ATP and GTP and 2'-OMe UTP and CTP ("dRmY") into transcripts the following conditions are preferred: HEPES buffer 200 mM, DTT 40 mM, spermine 2 mM, spermidine 2 mM, PEG-8000 10% (w/v), Triton X 100 0.01% (w/v), MgCl 2 9.6 mM, MnCl 2 2.9 mM, 2'-OMe NTP (each) 2.0 mM, pH 7.5, Y639F T7 RNA Polymerase 15 units/mL, inorganic pyrophosphatase 5 units/mL, and an all-purine leader sequence of at least 8 nucleotides long. [00122] For maximum incorporation (100%) of 2'-OMe ATP, UTP and CTP and 2'-F GTP ("fGmH") into transcripts the following conditions are preferred: HEPES buffer 200 mM, DTT 40 mM, spermidine 2 mM, PEG-8000 10% (w/v), Triton X-100 0.01% (w/v), MgCl 2 9.6 mM, MnCl 2 2.9 mM, 2'-OMe NTP (each) 2.0 mM, pH 7.5, Y639F T7 RNA Polymerase 15 units/mnL, inorganic pyrophosphatase 5 units/mL, and an all-purine leader sequence of at least 8 nucleotides long. [00123] For maximum incorporation (100%) of deoxy ATP and 2'-OMe UTP, GTP and CTP ("dAmB") into transcripts the following conditions are preferred: HEPES buffer 200 mM, DTT 40 mM, spermidine 2 mM, PEG-8000 10% (w/v), Triton X-100 0.01% (w/v), MgCl 2 9.6 mM, MnCl 2 2.9 mM, 2'-OMe NTP (each) 2.0 mM, pH 7.5, Y639F T7 RNA Polymerase 15 units/mL, inorganic pyrophosphatase 5 units/mL, and an all-purine leader sequence of at least 8 nucleotides long. [001241 For each of the above (a) transcription is preferably performed at a temperature of from about 20 'C to about 50 'C, preferably from about 30 0 C to 45 'C, and more preferably at about 37 'C for a period of at least two hours and (b) 50-300 nM of a double stranded DNA transcription template is used (200 nM template is used in round 1 to increase diversity (300 nM template is used in dRmY transcriptions)), and for subsequent rounds approximately 50 nM, a 1/10 dilution of an optimized PCR reaction, using 34 WO 2007/035922 PCT/US2006/037276 conditions described herein, is used). The preferred DNA transcription templates are described below (where ARC254 and ARC256 transcribe under all 2'-OMe conditions and ARC255 transcribes under rRmY conditions). SEQ ID NO 1 (ARC254) 5'-CATCGATGCTAGTCGTAACGATCCNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNCGAGAACGTTCTCTCCTCTCCCTA TAGTGAGTCGTATTA-3' SEQ ID NO 2 (ARC255) 5'-CATGCATCGCGACTGACTAGCCGNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNGTAGAACGTTCTCTCCTCTCCCTAT AGTGAGTCGTATTA-3' SEQ ID NO 3 (ARC256) 5'-CATCGATCGATCGATCGACAGCGNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNGTAGAACGTTCTCTCCTCTCCCTAT AGTGAGTCGTATTA-3' [00125] Under rN transcription conditions of the present invention, the transcription reaction mixture comprises 2'-OH adenosine triphosphates (ATP), 2'-OH guanosine triphosphates (GTP), 2'-OH cytidine triphosphates (CTP), and 2'-OH uridine triphosphates (UTP). The modified oligonucleotides produced using the rN transcription mixtures of the present invention comprise substantially all 2'-OH adenosine, 2'-OH guanosine, 2'-OH cytidine, and 2'-OH uridine. In a preferred embodiment of rN transcription, the resulting modified oligonucleotides comprise a sequence where at least 80% of all adenosine nucleotides are 2'-OH adenosine, at least 80% of all guanosine nucleotides are 2'-OH guanosine, at least 80% of all cytidine nucleotides are 2'-OH cytidine, and at least 80% of all uridine nucleotides are 2'-OH uridine. In a more preferred embodiment of rN transcription, the resulting modified oligonucleotides of the present invention comprise a sequence where at least 90% of all adenosine nucleotides are 2'-OH adenosine, at least 90% of all guanosine nucleotides are 2'-OH guanosine, at least 90% of all cytidine nucleotides are 2'-OH cytidine, and at least 90% of all uridine nucleotides are 2'-OH uridine. In a most preferred embodiment of rN transcription, the modified oligonucleotides of the present invention comprise a sequence where 100% of all adenosine nucleotides are 2'-OH adenosine, 100% of all guanosine nucleotides are 2'-OH guanosine, 100% of all cytidine nucleotides are 2'-OH cytidine, and 100% of all uridine nucleotides are 2'-OH uridine. [001261 Under rRmY transcription conditions of the present invention, the transcription reaction mixture comprises 2'-OH adenosine triphosphates, 2'-OH guanosine triphosphates, 2'-O-methyl cytidine triphosphates, and 2'-O-methyl uridine triphosphates. The modified oligonucleotides produced using the rRmY transcription mixtures of the present invention comprise substantially all 2'-OH adenosine, 2'-OH guanosine, 2'-O-methyl cytidine and 2' 35 WO 2007/035922 PCT/US2006/037276 O-methyl uridine. In a preferred embodiment, the resulting modified oligonucleotides comprise a sequence where at least 80% of all adenosine nucleotides are 2'-OH adenosine, at least 80% of all guanosine nucleotides are 2'-OH guanosine, at least 80% of all cytidine nucleotides are 2'-0-methyl cytidine and at least 80% of all uridine nucleotides are 2'-O methyl uridine. In a more preferred embodiment, the resulting modified oligonucleotides comprise a sequence where at least 90% of all adenosine nucleotides are 2'-OH adenosine, at least 90% of all guanosine nucleotides are 2'-OH guanosine, at least 90% of all cytidine nucleotides are 2'-0-methyl cytidine and at least 90% of all uridine nucleotides are 2'-0 methyl uridine In a most preferred embodiment, the resulting modified oligonucleotides comprise a sequence where 100% of all adenosine nucleotides are 2'-OH adenosine, 100% of all guanosine nucleotides are 2'-OH guanosine, 100% of all cytidine nucleotides are 2' 0-methyl cytidine and 100% of all uridine nucleotides are 2'-O-methyl uridine. [001271 Under dRmY transcription conditions of the present invention, the transcription reaction mixture comprises 2'-deoxy adenosine triphosphates, 2'-deoxy guanosine triphosphates, 2'-O-methyl cytidine triphosphates, and 2'-0-methyl uridine triphosphates. The modified oligonucleotides produced using the dRmY transcription conditions of the present invention comprise substantially all 2'-deoxy adenosine, 2'-deoxy guanosine, 2'-0 methyl cytidine, and 2'-0-methyl uridine. In a preferred embodiment, the resulting modified oligonucleotides of the present invention comprise a sequence where at least 80% of all adenosine nucleotides are 2'-deoxy adenosine, at least 80% of all guanosine nucleotides are 2'-deoxy guanosine, at least 80% of all cytidine nucleotides are 2'-O-methyl cytidine, and at least 80% of all uridine nucleotides are 2'-0-methyl uridine. In a more preferred embodiment, the resulting modified oligonucleotides of the present invention comprise a sequence where at least 90% of all adenosine nucleotides are 2'-deoxy adenosine, at least 90 % of all guanosine nucleotides are 2'-deoxy guanosine, at least 90% of all cytidine nucleotides are 2'-0-methyl cytidine, and at least 90% of all uridine nucleotides are 2'-0-methyl uridine. In a most preferred embodiment, the resulting modified oligonucleotides of the present invention comprise a sequence where 100% of all adenosine nucleotides are 2'-deoxy adenosine, 100% of all guanosine nucleotides are 2' deoxy guanosine, 100% of all cytidine nucleotides are 2'-0-methyl cytidine, and 100% of all uridine nucleotides are 2'-O-methyl uridine. 36 WO 2007/035922 PCT/US2006/037276 [001281 Under rGmH transcription conditions of the present invention, the transcription reaction mixture comprises 2'-OH guanosine triphosphates, 2'-O-methyl cytidine triphosphates, 2'-0-methyl uridine triphosphates, and 2'-O-methyl adenosine triphosphates. The modified oligonucleotides produced using the rGmH transcription mixtures of the present invention comprise substantially all 2'-OH guanosine, 2'-O-methyl cytidine, 2'-0 methyl uridine, and 2'-0-methyl adenosine. In a preferred embodiment, the resulting modified oligonucleotides comprise a sequence where at least 80% of all guanosine nucleotides are 2'-OH guanosine, at least 80% of all cytidine nucleotides are 2'-O-methyl cytidine, at least 80% of all uridine nucleotides are 2'-0-methyl uridine, and at least 80% of all adenosine nucleotides are 2'-O-methyl adenosine. In a more preferred embodiment, the resulting modified oligonucleotides comprise a sequence where at least 90% of all guanosine nucleotides are 2'-OH guanosine, at least 90% of all cytidine nucleotides are 2' 0-methyl cytidine, at least 90% of all uridine nucleotides are 2'-0-methyl uridine, and at least 90% of all adenosine nucleotides are 2'-O-methyl adenosine. In a most preferred embodiment, the resulting modified oligonucleotides comprise a sequence where 100% of all guanosine nucleotides are 2'-OH guanosine, 100% of all cytidine nucleotides are 2'-O methyl cytidine, 100% of all uridine nucleotides are 2'-O-methyl uridine, and 100% of all adenosine nucleotides are 2'-O-methyl adenosine. [00129] Under r/mGmH transcription conditions of the present invention, the transcription reaction mixture comprises 2'-O-methyl adenosine triphosphate, 2'-0-methyl cytidine triphosphate, 2'-O-methyl guanosine triphosphate, 2'-0-methyl uridine triphosphate and 2'-OH guanosine triphosphate. The resulting modified oligonucleotides produced using the r/mGmH transcription mixtures of the present invention comprise substantially all 2'-O-methyl adenosine, 2'-0-methyl cytidine, 2'-0-methyl guanosine, and 2'-0-methyl uridine, wherein the population of guanosine nucleotides has a maximum of about 10% 2'-OH guanosine. In a preferred embodiment, the resulting r/mGmH modified oligonucleotides of the present invention comprise a sequence where at least 80% of all adenosine nucleotides are 2'-O-methyl adenosine, at least 80% of all cytidine nucleotides are 2'-0-methyl cytidine, at least 80% of all guanosine nucleotides are 2'-0-methyl guanosine, at least 80% of all uridine nucleotides are 2'-0-methyl uridine, and no more than about 10% of all guanosine nucleotides are 2'-OH guanosine. In a more preferred embodiment, the resulting modified oligonucleotides comprise a sequence where at least 37 WO 2007/035922 PCT/US2006/037276 90% of all adenosine nucleotides are 2'-0-methyl adenosine, at least 90% of all cytidine nucleotides are 2'-O-methyl cytidine, at least 90% of all guanosine nucleotides are 2'-0 methyl guanosine, at least 90% of all uridine nucleotides are 2'-O-methyl uridine, and no more than about 10% of all guanosine nucleotides are 2'-OH guanosine. In a most preferred embodiment, the resulting modified oligonucleotides comprise a sequence where 100% of all adenosine nucleotides are 2'-O-methyl adenosine, 100% of all cytidine nucleotides are 2'-O-methyl cytidine, 90% of all guanosine nucleotides are 2'-0-methyl guanosine, and 100% of all uridine nucleotides are 2'-O-methyl uridine, and no more than about 10% of all guanosine nucleotides are 2'-OH guanosine. [00130] Under fGmH transcription conditions of the present invention, the transcription reaction mixture comprises 2'-O-methyl adenosine triphosphates, 2'-0-methyl uridine triphosphates, 2'-0-methyl cytidine triphosphates, and 2'-F guanosine triphosphates. The modified oligonucleotides produced using the fGrnH transcription conditions of the present invention comprise substantially all 2'-0-methyl adenosine, 2'-O-methyl uridine, 2'-0 methyl cytidine, and 2'-F guanosine. In a preferred embodiment, the resulting modified oligonucleotides comprise a sequence where at least 80% of all adenosine nucleotides are 2'-0-methyl adenosine, at least 80% of all uridine nucleotides are 2'-0-methyl uridine, at least 80% of all cytidine nucleotides are 2'-O-methyl cytidine, and at least 80% of all guanosine nucleotides are 2'-F guanosine. In a more preferred embodiment, the resulting modified oligonucleotides comprise a sequence where at least 90% of all adenosine nucleotides are 2'-0-methyl adenosine, at least 90% of all uridine nucleotides are 2'-0 methyl uridine, at least 90% of all cytidine nucleotides are 2'-0-methyl cytidine, and at least 90% of all guanosine nucleotides are 2'-F guanosine. In a most preferred embodiment, the resulting modified oligonucleotides comprise a sequence where 100% of all adenosine nucleotides are 2'-0-methyl adenosine, 100% of all uridine nucleotides are 2'-0-methyl uridine, 100% of all cytidine nucleotides are 2'-O-methyl cytidine, and 100% of all guanosine nucleotides are 2'-F guanosine. [00131] Under dAmB transcription conditions of the present invention, the transcription reaction mixture comprises 2'-deoxy adenosine triphosphates, 2'-0-methyl cytidine triphosphates, 2'-0-methyl guanosine triphosphates, and 2'-O-methyl uridine triphosphates. The modified oligonucleotides produced using the dAmB transcription mixtures of the 38 WO 2007/035922 PCT/US2006/037276 present invention comprise substantially all 2'-deoxy adenosine, 2'-O-methyl cytidine, 2'-0 methyl guanosine, and 2'-O-methyl uridine. In a preferred embodiment, the resulting modified oligonucleotides comprise a sequence where at least 80% of all adenosine nucleotides are 2'-deoxy adenosine, at least 80% of all cytidine nucleotides are 2'-O-methyl cytidine, at least 80% of all guanosine nucleotides are 2'-0-methyl guanosine, and at least 80% of all uridine nucleotides are 2'-O-methyl uridine. In a more preferred embodiment, the resulting modified oligonucleotides comprise a sequence where at least 90% of all adenosine nucleotides are 2'-deoxy adenosine, at least 90% of all cytidine nucleotides are 2'-O-methyl cytidine, at least 90% of all guanosine nucleotides are 2'-O-methyl guanosine, and at least 90% of all uridine nucleotides are 2'-O-methyl uridine. In a most preferred embodiment, the resulting modified oligonucleotides of the present invention comprise a sequence where 100% of all adenosine nucleotides are 2'-deoxy adenosine, 100% of all cytidine nucleotides are 2'-O-methyl cytidine, 100% of all guanosine nucleotides are 2'-0 methyl guanosine, and 100% of all uridine nucleotides are 2'-O-methyl uridine. [00132] In each case, the transcription products can then be used as the library in the SELEXT process to identify aptamers and/or to determine a conserved motif of sequences that have binding specificity to a given target. The resulting sequences are already partially stabilized, eliminating this step from the process to arrive at an optimized aptamer sequence and giving a more highly stabilized aptaner as a result. Another advantage of the 2'-OMe SELEX7 process is that the resulting sequences are likely to have fewer 2'-OH nucleotides required in the sequence, possibly none. To the extent 2'OH nucleotides remain they can be removed by perfonning post-SELEXM modifications. [00133] As described below, lower but still useful yields of transcripts fully incorporating 2' substituted nucleotides can be obtained under conditions other than the optimized conditions described above. For example, variations to the above transcription conditions include: [001341 The HEPES buffer concentration can range from 0 to 1 M. The present invention also contemplates the use of other buffering agents having a pKa between 5 and 10 including, for example, Tris-hydroxymethyl-aminomethane. 39 WO 2007/035922 PCT/US2006/037276 [00135] The DTT concentration can range from 0 to 400 mM. The methods of the present invention also provide for the use of other reducing agents including, for example, mercaptoethanol. [001361 The spermidine and/or spermine concentration can range from 0 to 20 mM. [00137] The PEG-8000 concentration can range from 0 to 50 % (w/v). The methods of the present invention also provide for the use of other hydrophilic polymer including, for example, other molecular weight PEG or other polyalkylene glycols. [00138] The Triton X-100 concentration can range from 0 to 0.1% (w/v). The methods of the present invention also provide for the use of other non-ionic detergents including, for example, other detergents, including other Triton-X detergents. [00139] The MgCl 2 concentration can range from 0.5 mM to 50 mM. The MnCl 2 concentration can range from 0.15 mM to 15 mM. Both MgCl 2 and MnC 2 must be present within the ranges described and in a preferred embodiment are present in about a 10 to about 3 ratio of MgCl 2 :MnCI 2 , preferably, the ratio is about 3-5:1, more preferably, the ratio is about 3-4:1. [00140] The 2'-OMe NTP concentration (each NTP) can range from 5 .M to 5 mM. [00141] The 2'-OH GTP concentration can range from 0 pM to 300 pM. [00142] The 2'-OH GMP concentration can range from 0 to 5 mM. [00143] The pH can range from pH 6 to pH 9. The methods of the present invention can be practiced within the pH range of activity of most polymerases that incorporate modified nucleotides. In addition, the methods of the present invention provide for the optional use of chelating agents in the transcription reaction condition including, for example, EDTA, EGTA, and DTT. IL-23 AND/OR IL-12 APTAMER SELECTION STRATEGIES. [00144] The present invention provides aptamers that bind to human IL-23 and/or IL-12 and in some embodiments, inhibit binding to their receptor and/or otherwise modulate their function. Human IL-23 and IL-12 are both heterodimers that have one subunit in common and one unique. The subunit in common is the p40 subunit which contains the following amino acid sequence (Accession # AF 80563) (SEQ ID NO 4): MCHQQLVISWFSLVFLASPLVAIWELKKDVYVVELDWYPDAPGE 40 WO 2007/035922 PCT/US2006/037276 MVVLTCDTPEEDGITWTLDQSSEVLGSGKTLTIQVKEFGDAGQYTCHKGGEVLSHS LL LLHKKEDGIWSTDILKDQKEPKNKTFLRCEAKNYSGRFTCWWLTTISTDLTFSVKSS R GSSDPQGVTCGAATLSAERVRGDNKEYEYSVECQEDSACPAAEESLPIEVMVDAV HIKL KYENYTSSFFIRDIIKPDPPECNLQLKPLKNSRQVEVSWEYPDTWSTPHSYFSLTFCVQ VQGKSKREKKDRVFTDKTSATVICRKNASISVRAQDRYYSSSWSEWASVPCS. [00011 The p19 subunit is unique to IL-23 and contains the following amino acid sequence (Accession # BC0675 11) (SEQ ID NO 5): MLGSRAVMLLLLLPWTAQGRAVPGGSSPAWTQCQQLSQKLCTLA WSAHPLVGHMDLREEGDEETTNDVPHIQCGDGCDPQGLRDNSQFCLQRIHQGLIFY EK LLGSDIFTGEPSLLPDSPVGQLHASLLGLSQLLQPEGHHWETQQIPSLSPSQPWQRLL LRFKILRSLQAFVAVAARVFAHGAATLSP. [00145] The p35 subunit is unique to IL-12 and contains the following amino acid sequence (Accession # AF180562) (SEQ ID NO 6): MWPPGSASQPPPSPAAATGLHPAARPVSLQCRLSMCPARSLLLV ATLVLLDHLSLARNLPVATPDPGMFPCLHHSQNLLRAVSNMLQKARQTLEFYPCTS EE IDHEDITKDKTSTVEACLPLELTKNESCLNSRETSFITNGSCLASRKTSFMMALCLSS IYEDLKMYQVEFKTMNAKLLMDPKRQIFLDQNMLAVIDELMQALNFNSETVPQKS SLE EPDFYKTKIKLCILLHAFRIRAVTIDRVMSYLNAS. [00146] The present invention also provides aptamers that bind to mouse IL-23 and/or IL-12 and in some embodiments, inhibit binding to their receptor and/or otherwise modulate their function. Like human, mouse IL-23 and IL- 12 are both heterodimers that share the mouse p40 subunit, while the mouse p19 subunit is specific to mouse IL-23 and the mouse 41 WO 2007/035922 PCT/US2006/037276 p35 subunit is unique to mouse IL-12. The mouse p40 subunit contains the following amino acid sequence (Accession # P43432) (SEQ ID NO 321): MCPQKLTISWFAIVLLVSPLMAMWELEKDVYVVEVDWTPDAPGETVNLTCDTPEE DDITWTSDQRHGVIGSGKTLTITVKEFLDAGQYTCHKGGETLSHSHLLLHKKENGI WSTEILKNFKNKTFLKCEAPNYSGRFTCSWLVQRNMDLKFNIKSSSSSPDSRAVTC GMASLSAEKVTLDQRDYEKYSVSCQEDVTCPTAEETLPIELALEARQQNKYENYST SFFIRDIIKPDPPKNLQMKPLKNSQVEVSWEYPDSWSTPHSYFSLKFFVRIQRKKEK MKETEEGCNQKGAFLVEKTSTEVQCKGGNVCVQAQDRYYNSSCSKWACVPCRVR S [00147] The mouse p19 subunit contains the following amino acid sequence (Accession # NP 112542 ) (SEQ ID NO 322): MLDCRAVIMLWLLPWVTQGLAVPRSSSPDWAQCQQLSRNLCMLAWNAHAP AGHMNLLREEEDEETKNNVPRIQCEDGCDPQGLKDNSQFCLQRIRQGLAF YKHLLDSDIF KGEPALLPDSPMEQLHTSLLGLSQLLQPEDHPRETQQMPS LSSSQQWQRPLLRSKILRSLQAFLAIAARVFAHGAATLTE PLVPTA [00148] The mouse p35 subunit contains the following amino acid sequence (Accession # P43431 ) (SEQ ID NO 323): MCQSRYLLFLATLALLNHLSLARVIPVSGPARCLSQSRNLLKTTDDMVKTAREKLK H-YSCTAEDIDHEDITRDQTSTLKTCLPLELHKNESCLATRETSSTTRGSCLPPQKTSL MMTLCL GSIYEDLKMYQTEFQAINAALQNHNHQQIILDKGMLVAIDELMQSLNHNGETLRQK PPVGEADPYRVKMKLCILLHAFST RVVTINRVMG YLSSA [00149] Several SELEX m strategies can be employed to generate aptamers with a variety of specificities for IL-23 and IL-12. One scheme produces aptamers specific for IL-23 over IL-12 by including IL-12 in a negative selection step. This eliminates sequences that recognize the common subunit, p40 (SEQ ID NO 4), and selects for aptamers specific to IL 42 WO 2007/035922 PCT/US2006/037276 23, or the p19 subunit (SEQ ID NO 5) as shown in Figure 3. One scheme produces aptamers specific for IL-12 over IL-23 by including IL-23 in the negative selection step. This eliminates sequences that recognize the common subunit, p40 (SEQ ID NO 4) and selects for aptamers specific for IL-12, or the p35 subunit (SEQ ID NO 6). A separate selection in which IL-23 and IL- 12 are alternated every other round elicits aptamers that recognize the common subunit, p40 (SEQ ID NO 4), and therefore recognizes both proteins. Once sequences with the desired binding specificity are found, minimization of those sequences can be undertaken to systematically reduce the size of the sequences with concomitant improvement in binding characteristics. [00150] The selected aptamers having the highest affinity and specific binding as demonstrated by biological assays as described in the examples below are suitable therapeutics for treating conditions in which IL-23 and/or IL-12 is involved in pathogenesis. IL-23/IL-12 SPECIFIC BINDING APTAMERS [00151] The materials of the present invention comprise a series of nucleic acid aptamers of -25-90 nucleotides in length which bind specifically to cytokines of the human IL-12 cytokine family which includes IL-12, IL-23, and IL-27; p19, p35, and p40 subunit monomers; and p40 subunit diners; and which functionally modulate, e.g., block, the activity of IL-23 and/or IL- 12 in in vivo and/or in cell-based assays. [00152] Aptamers specifically capable of binding and modulating IL-23 and/or IL- 12 are set forth herein. These aptamers provide a low-toxicity, safe, and effective modality of treating and/or preventing autoimmune and inflammatory related diseases or disorders. In one embodiment, the aptamers of the invention are used to treat and/or prevent inflammatory and autoimmune diseases, including but not limited to, multiple sclerosis, rheumatoid arthritis, psoriasis vulgaris, and irritable bowel disease, including without limitation Crohn's disease, and ulcerative colitis, each of which are known to be caused by or otherwise associated with the IL-23 and/or IL-12 cytokine. In another embodiment, the aptamers of the invention are used to treat and/or prevent Type I Diabetes, which is known to be caused by or otherwise associated with the IL-23 and/or IL-12 cytokine. In another embodiment, the aptamers of the invention are used to treat and/or prevent other indications for which activation of cytokine receptor binding is desirable including, for example, 43 WO 2007/035922 PCT/US2006/037276 systemic lupus erythamatosus, colon cancer, lung cancer, and bone resorption in osteoporosis. [001531 Examples of IL-23 and/or IL-12 specific binding aptamers for use as therapeutics and/or diagnostics include the following sequences listed below. [00154] Unless noted otherwise, ARC489 (SEQ ID NO 91), ARC491 (SEQ ID NO 94), ARC621 (SEQ ID NO 108), ARC627 (SEQ ID NO 110), ARC527 (SEQ ID NO 159), ARC792 (SEQ ID NO 162), ARC794 (SEQ ID NO 164), ARC795 (SEQ ID NO 165), ARC979 (SEQ ID NO 177), ARC1386 (SEQ ID NO 224), and ARC1623-ARC1625 (SEQ ID NOs 309-311) represent the sequences of the aptamers that bind to IL-23 and/or IL-12 that were selected under SELEX' conditions in which the purines (A and G) are deoxy, and the pyrimidines (C and U) are 2'-OMe. [00155] The unique sequence region of ARC489 (SEQ ID NO 91) and ARC491 (SEQ ID NO 94) begins at nucleotide 23, immediately following the sequence GGGAGAGGAGAGAACGUUCUAC (SEQ ID NO 69), and runs until it meets the 3'fixed nucleic acid sequence GCUGUCGAUCGAUCGAUCGAUG (SEQ ID NO 90). [00156] The unique sequence region of ARC621 (SEQ ID NO 108) and ARC627 (SEQ ID NO 110) begins at nucleotide 23, immediately following the sequence GGGAGAGGAGAGAACGUUCUAC (SEQ ID NO 101), and runs until it meets the 3'fixed nucleic acid sequence GUCGAUCGAUCGAUCAUCGAUG (SEQ ID NO 102). SEQ ID NO 91 (ARC489) GGGAGAGGAGAGAACGUUCUACAGCGCCGGUGGGCGGGCAUUGGGUGGAUGCGCUGUCGAUCGALICGAUCGAUG SEQ ID NO 94 (ARC491) GGGAGAGGAGAGAACGUUCUACAGCGCCGGUGGGUGGGCAUAGGGUGGAUGCGCUGUCGAUCGAICGAUCGAUG SEQ ID NO 108 (ARC621) GGGAGAGGAGAGAACGUUCUACAGGCGGUUACGGGGGAUGCGGGUGGGACAGGUCGAUCGAUCGAUCAUCGAUG SEQ ID NO 110 (ARC627) GGGAGAGGAGAGAACGUUCUACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGUCGAUCGAUCGAUCAUCGAUG SEQ ID NO 159 (ARC527) ACAGCGCCGGUGGGCGGGCAUUGGGUGGAUGCGCUGU SEQ ID NO 162 (ARC792) GGCAAGUAAUUGGGGAGUGCGGGCGGGG 44 WO 2007/035922 PCT/US2006/037276 SEQ ID NO 164 (ARC794) GGCGGUACGGGGAGUGUGGGUUGGGGCCGG SEQ ID NO 165 (ARC795) CGAUAUAGGCGGUACGGGGGAGIGGGCUGGGGUCG SEQ ID NO 177 (ARC979) ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU [00157] ARC1623 (SEQ ID NO 309), ARC1624 (SEQ ID NO 310) and ARC1625 (SEQ ID NO 311) represent optimized sequences based on ARC979 (SEQ ID NO 177), where "d" stands for deoxy, "m" stands for 2'-O-methyl, "s" indicates a phosphorothioate internucleotide linkage, and "3T" stands for a 3'-inverted deoxy thymidine. SEQ ID NO 309 (ARC1623) dAnCdAdGdGmCdAdAdGmUdAdAnUnUdGnGmG-s-dG-s-dA-s-dGmU-s-dGmCmGmGdGmCdGdGmGmGmUdGmU-3T SEQ ID NO 310 (ARC1624) dAmCdAdG(IGmCdAdAdGmUdAdAmUnUdGmGmGdGdAdGmUdGmCmGmG-s-dGmC-s-dG-s-dGnmGmGmUdGmU-3T SEQ ID NO 311 (ARC1625) dAnCdAdGdGnCdAdAdGmUdAdAmUmUdGmGnGdGdAcGmUdGmCmGmGdGnCdGdGmGniGmU-s-dGnU-3T [00158] SEQ ID NOS 139-140, SEQ ID NOS 144-145, SEQ ID NO 147, and SEQ ID NOS 151-152, represent the sequences of the aptamers that bind to IL-23 and/or IL-12 that were selected under SELEX" conditions in which the purines (A and G) are 2'-OH (ribo) and the pyrimidines (C and U) are 2'-Fluoro. SEQ ID NO 139 (A10.min5) GGAGCAUACACAAGAAGUUUUUUGUGCUCUGAGUACUCAGCGUCCGUAAGGGAUAUGCUCC SEQ ID NO 140 (A1O.min6) GGAGUACGCCGAAAGGCGCUCUGAGUACUCAGCGUCCGUAAGGGAUACUCC SEQ ID NO 144 (B1O.min4) GGAGCAUACACAAGAAGUGCUUCAUGCGGCAAACUGCAUGACGUCGAAUAGAUAUGCUCC SEQ ID NO 145 (B1n.min5) GGAGUACACAAGAAGUGCUUCCGAAAGGACGUCGAAUAGAUACUCC SEQ ID NO 147 (F11.min2) GGACAUACACAAGAUGUGCUUGAGUUAAAUCUCAUCGUCCCCGUUUGGGGAUAUGUC SEQ ID NO 151 45 WO 2007/035922 PCT/US2006/037276 GGGUACGCCGAAAGGCGCUUCCGAAAGGACGUCCGUAAGGGAUACCC SEQ ID NO 152 GGAGUACGCCGAAAGGCGCUUCCGAAAGGACGUCCGUAAGGGAUACUCC [00159] Other aptamers that bind IL-23 and/or IL-12 are described below in Examples 1 3. [00160] These aptamers may include modifications as described herein including e.g., conjugation to lipophilic or high molecular weight compounds (e.g., PEG), incorporation of a CpG motif, incorporation of a capping moiety, incorporation of modified nucleotides, and incorporation of phosphorothioate in the phosphate backbone. [001611 In one embodiment, an isolated, non-naturally occurring aptamer that binds to IL-23 and/or IL-12 is provided. In some embodiments, the isolated, non-naturally occurring aptamer has a dissociation constant ("KD") for IL-23 and/or IL-12 of less than 100 pM, less than 1 plVI, less than 500 nM, less than 100 nM, less than 50 nM, less than I nM, less than 500 pM, less than 100 pM, and less than 50 pM. In some embodiments of the invention, the dissociation constant is determined by dot blot titration as described in Example 1 below. [001621 In another embodiment, the aptamer of the invention modulates a function of IL 23 and/or IL-12. In another embodiment, the aptamer of the invention inhibits an IL-23 and/or IL- 12 function while in another embodiment the aptamer stimulates a function of the target. In another embodiment of the invention, the aptamer binds and/or modulates a function of an IL-23 or IL- 12 variant. An IL-23 or IL- 12 variant as used herein encompasses variants that perform essentially the same function as an IL-23 or IL- 12 function, preferably comprises substantially the same structure and in some embodiments comprises at least 70% sequence identity, preferably at least 80% sequence identity, more preferably at least 90% sequence identity, and more preferably at least 95% sequence identity to the amino acid sequence of IL-23 or IL-12. In some embodiments of the invention, the sequence identity of target variants is determined using BLAST as described below. [00163] The terms "sequence identity" in the context of two or more nucleic acid or protein sequences, refer to two or more sequences or subsequences that are the same or have a specified percentage of amino acid residues or nucleotides that are the same, when compared and aligned for maximum correspondence, as measured using one of the 46 WO 2007/035922 PCT/US2006/037276 following sequence comparison algorithms or by visual inspection. For sequence comparison, typically one sequence acts as a reference sequence to which test sequences are compared. When using a sequence comparison algorithm, test and reference sequences are input into a computer, subsequence coordinates are designated if necessary, and sequence algorithm program parameters are designated. The sequence comparison algorithm then calculates the percent sequence identity for the test sequence(s) relative to the reference sequence, based on the designated program parameters. Optimal alignment of sequences for comparison can be conducted, e.g., by the local homology algorithm of Smith & Watennan, Adv. Appl. Math. 2: 482 (1981), by the homology aligmnent algorithm of Needleman & Wunsch, J Mol. Biol. 48: 443 (1970), by the search for similarity method of Pearson & Lipman, Proc. Nat'l. Acad. Sci. USA 85: 2444 (1988), by computerized implementations of these algorithms (GAP, BESTFIT, FASTA, and TFASTA in the Wisconsin Genetics Software Package, Genetics Computer Group, 575 Science Dr., Madison, Wis.), or by visual inspection (see generally, Ausubel et al., infra). [001641 One example of an algorithm that is suitable for determining percent sequence identity is the algorithm used in the basic local alignment search tool (hereinafter "BLAST'), see, e.g. Altschul et al., J Mol. Biol. 215: 403-410 (1990) and Altschul et al., Nucleic Acids Res., 15: 3389-3402 (1997). Software for performing BLAST analyses is publicly available through the National Center for Biotechnology Information (hereinafter "NCBI"). The default parameters used in determining sequence identity using the software available from NCBI, e.g., BLASTN (for nucleotide sequences) and BLASTP (for amino acid sequences) are described in McGinnis et al., Nucleic Acids Res., 32: W20-W25 (2004). [00165] In one embodiment of the invention, the aptamer has substantially the same ability to bind to IL-23 as that of an aptamer comprising any one of SEQ ID NOs 13-66, SEQ ID NOs 71-88, SEQ ID NOs 91-96, SEQ ID NOs 103-118, SEQ ID NOs 124-134, SEQ ID NOs 135-159, SEQ ID NO 162, and SEQ ID NOs 164-172, SEQ ID NOs 176-178, SEQ ID NOs 181-196, and SEQ ID NOs 199-314. In another embodiment of the invention, the aptamer has substantially the same structure and ability to bind to IL-23 as that of an aptamer comprising any one of SEQ ID NOs 13-66, SEQ ID NOs 71-88, SEQ ID NOs 91 96, SEQ ID NOs 103-118, SEQ ID NOs 124-134, SEQ ID NOs 135-159, SEQ ID NO 162, and SEQ ID NOs 164-172, SEQ ID NOs 176-178, SEQ ID NOs 181-196, and SEQ ID NOs 199-314. 47 WO 2007/035922 PCT/US2006/037276 [00166] In one embodiment of the invention, the aptamer has substantially the same ability to bind to IL-23 and/or IL-12 as that of an aptamer comprising any one of SEQ ID NO 14, SEQ ID NOs 17-19, SEQ ID NO 21, SEQ ID NOs 27-32, SEQ ID NOs 34-40, SEQ ID NO 42, SEQ ID NO 49, SEQ ID NOs 60-61, SEQ ID NOs 91-92, SEQ ID NO 94, and SEQ ID NOs 103-118. In another embodiment of the invention, the aptamer has substantially the same structure and ability to bind to IL-23 and/or IL- 12 as that of an aptamer comprising any one of SEQ ID NO 14, SEQ ID NOs 17-19, SEQ ID NO 21, SEQ ID NOs 27-32, SEQ ID NOs 34-40, SEQ ID NO 42, SEQ ID NO 49, SEQ ID NOs 60-61, SEQ ID NOs 91-92, SEQ ID NO 94, and SEQ ID NOs 103-118. [00167] In another embodiment, the aptamers of the invention are used as an active ingredient in pharmaceutical compositions. In another embodiment, the aptamers or compositions comprising the aptamers of the invention are used to treat inflammatory and autoimmune diseases (including but not limited to, multiple sclerosis, rheumatoid arthritis, psoriasis vulgaris, systemic lupus erythamatosus, and irritable bowel disease, including without limitation Crohn's disease, and ulcerative colitis), Type I Diabetes, colon cancer, lung cancer, and bone resorption in osteoporosis. [00168] In some embodiments aptamer therapeutics of the present invention have great affinity and specificity to their targets while reducing the deleterious side effects from non naturally occurring nucleotide substitutions if the aptamer therapeutics break down in the body of patients or subjects. In some embodiments, the therapeutic compositions containing the aptamer therapeutics of the present invention are free of or have a reduced amount of fluorinated nucleotides. [001691 The aptamers of the present invention can be synthesized using any oligonucleotide synthesis techniques known in the art including solid phase oligonucleotide synthesis techniques (see, e.g., Froehler et al., Nucl. Acid Res. 14:5399-5467 (1986) and Froehler et al., Tet. Lett. 27:5575-5578 (1986)) and solution phase methods well known in the art such as triester synthesis methods (see, e.g., Sood et al., Nucl. Acid Res. 4:2557 (1977) and Hirose et al., Tet. Lett., 28:2449 (1978)). APTAMERS HAVING IMMUNOSTIMULATORY MOTIFS [00170] The present invention provides aptamers that bind to IL-23 and/or IL-12 and modulate their biological function. More specifically, the present invention provides aptamers that increase the binding of IL-23 and/or IL- 12 to the IL-23 and/or IL- 12 receptor 48 WO 2007/035922 PCT/US2006/037276 thereby enhancing the biological function of IL-23 and/or IL-12. The agonistic effect of such aptamers can be further enhanced by selecting for aptamers which bind to the IL-23 and/or IL-12 and contain immunostimulatory motifs, or by treating with aptamers which bind to IL-23 and/or IL- 12 in conjunction with aptamers to a target known to bind immunostimulatoiy sequences. [00171] Recognition of bacterial DNA by the vertebrate immune system is based on the recognition of unmethylated CG dinucleotides in particular sequence contexts ("CpG motifs"). One receptor that recognizes such a motif is Toll-like receptor 9 ("TLR 9"), a member of a family of Toll-like receptors (-10 members) that participate in the innate immune response by recognizing distinct microbial components. TLR 9 binds unmethylated oligodeoxynucleotide ("ODN") CpG sequences in a sequence-specific manner. The recognition of CpG motifs triggers defense mechanisms leading to innate and ultimately acquired immune responses. For example, activation of TLR 9 in mice induces activation of antigen presenting cells, up regulation of MHC class I and II molecules and expression of important co-stimulatoiy molecules and cytokines including IL-12 and IL-23. This activation both directly and indirectly enhances B and T cell responses, including robust up regulation of the THi cytokine IFN-gamma. Collectively, the response to CpG sequences leads to: protection against infectious diseases, improved immune response to vaccines, an effective response against asthma, and improved antibody-dependent cell-mediated cytotoxicity. Thus, CpG ODNs can provide protection against infectious diseases, function as immuno-adjuvants or cancer therapeutics (monotherapy or in combination with a mAb or other therapies), and can decrease asthma and allergic response. [00172] Aptamers of the present invention comprising one or more CpG or other immunostimulatory sequences can be identified or generated by a variety of strategies using, e.g., the SELEXN process described herein. The incorporated immunostimulatory sequences can be DNA, RNA and/or a combination DNA/RNA. In general the strategies can be divided into two groups. In group one, the strategies are directed to identifying or generating aptamers comprising both a CpG motif or other immunostimulatory sequence as well as a binding site for a target, where the target (hereinafter "non-CpG target") is a target other than one known to recognize CpG motifs or other immunostimulatory sequences and known to stimulates an immune response upon binding to a CpG motif. In some embodiments of the invention the non-CpG target is an IL-23 and/or IL12 target. The first strategy of this group comprises performing SELEX7 to obtain an aptamer to a specific 49 WO 2007/035922 PCT/US2006/037276 non-CpG target, preferably a target, e.g., IL-23 and/or IL-12, where a repressed immune response is relevant to disease development, using an oligonucleotide pool wherein a CpG motif has been incorporated into each member of the pool as, or as part of, a fixed region, e.g., in some embodiments the randomized region of the pool members comprises a fixed region having a CpG motif incorporated therein, and identifying an aptamer comprising a CpG motif. The second strategy of this group comprises performing SELEX7* to obtain an aptamer to a specific non-CpG target preferably a target, e.g., IL-23 and/or IL- 12, where a repressed immune response is relevant to disease development, and following selection appending a CpG motif to the 5' and/or 3' end or engineering a CpG motif into a region, preferably a non-essential region, of the aptamer. The third strategy of this group comprises performing SELEXM to obtain an aptamer to a specific non-CpG target, preferably a target, e.g., IL-23 and/or IL-12, where a repressed immune response is relevant to disease development, wherein during synthesis of the pool the molar ratio of the various nucleotides is biased in one or more nucleotide addition steps so that the randomized region of each member of the pool is enriched in CpG motifs, and identifying an aptamer comprising a CpG motif. The fourth strategy of this group comprises performing SELEX " to obtain an aptamer to a specific non-CpG target, preferably a target, e.g., IL-23 and/or IL- 12, where a repressed immune response is relevant to disease development, and identifying an aptamer comprising a CpG motif. The fifth strategy of this group comprises perfonning SELEX " to obtain an aptamer to a specific non-CpG target, preferably a target, e.g., IL-23 and/or IL-12, where a repressed immune response is relevant to disease development, and identifying an aptamer which, upon binding, stimulates an immune response but which does not comprise a CpG motif. [001731 In group two, the strategies are directed to identifying or generating aptamers comprising a CpG motif and/or other sequences that are bound by the receptors for the CpG motifs (e.g., TLR9 or the other toll-like receptors) and upon binding stimulate an immune response. The first strategy of this group comprises performing SELEX" to obtain an aptamer to a target known to bind to CpG motifs or other immunostimulatory sequences and upon binding stimulate an immune response using an oligonucleotide pool wherein a CpG motif has been incorporated into each member of the pool as, or as part of, a fixed region, e.g., in some embodiments the randomized region of the pool members comprise a fixed region having a CpG motif incorporated therein, and identifying an aptamer comprising a CpG motif. The second strategy of this group comprises performing SELEX7 to obtain an 50 WO 2007/035922 PCT/US2006/037276 aptamer to a target known to bind to CpG motifs or other immunostimulatory sequences and upon binding stimulate an immune response and then appending a CpG motif to the 5' and/or 3' end or engineering a CpG motif into a region, preferably a non-essential region, of the aptamer. The third strategy of this group comprises performing SELEX" to obtain an aptamer to a target known to bind to CpG motifs or other immunostimulatory sequences and upon binding stimulate an immune response wherein during synthesis of the pool, the molar ratio of the various nucleotides is biased in one or more nucleotide addition steps so that the randomized region of each member of the pool is enriched in CpG motifs, and identifying an aptamer comprising a CpG motif. The fourth strategy of this group comprises performing SELEX7 to obtain an aptamer to a target known to bind to CpG motifs or other immunostimulatory sequences and upon binding stimulate an immune response and identifying an aptamer comprising a CpG motif. The fifth strategy of this group comprises performing SELEX" to obtain an aptamer to a target known to bind to CpG motifs or other inuunostimulatory sequences, and identifying an aptamer which upon binding, stimulate an immune response but which does not comprise a CpG motif. [00174] A variety of different classes of CpG motifs have been identified, each resulting upon recognition in a different cascade of events, release of cytokines and other molecules, and activation of certain cell types. See, e.g., CpG Motifs in Bacterial DNA and Their Immune Effects, Annu. Rev. Immunol. 2002, 20:709-760, incorporated herein by reference. Additional immunostimulatory motifs are disclosed in the following U.S. Patents, each of which is incorporated herein by reference: U.S. Patent No. 6,207,646; U.S. Patent No. 6,239,116; U.S. Patent No. 6,429,199; U.S. Patent No. 6,214,806; U.S. Patent No. 6,653,292; U.S. Patent No. 6,426,434; U.S. Patent No. 6,514,948 and U.S. Patent No. 6,498,148. Any of these CpG or other immunostimulatory motifs can be incorporated into an aptamer. The choice of aptamers is dependent on the disease or disorder to be treated. Preferred immunostimulatory motifs are as follows (shown 5' to 3' left to right) wherein "r" designates a purine, "y" designates a pyrimidine, and "X" designates any nucleotide: AACGTTCGAG (SEQ ID NO 7); AACGTT; ACGT, rCGy; rrCGyy, XCGX, XXCGXX, and XiX 2 CGY1Y, wherein X 1 is G or A, X 2 is not C, Yi is not G and Y 2 is preferably T. [001751 In those instances where a CpG motif is incorporated into an aptamer that binds to a specific target other than a target known to bind to CpG motifs and upon binding stimulate an immune response (a "non-CpG target"), the CpG is preferably located in a non essential region of the aptamer. Non-essential regions of aptamers can be identified by site 51 WO 2007/035922 PCT/US2006/037276 directed mutagenesis, deletion analyses and/or substitution analyses. However, any location that does not significantly interfere with the ability of the aptamer to bind to the non-CpG target may be used. In addition to being embedded within the aptamer sequence, the CpG motif may be appended to either or both of the 5' and 3' ends or otherwise attached to the aptamer. Any location or means of attachment may be used so long as the ability of the aptamer to bind to the non-CpG target is not significantly interfered with. [00176] As used herein, "stimulation of an immune response" can mean either (1) the induction of a specific response (e.g., induction of a Th1 response) or of the production of certain molecules or (2) the inhibition or suppression of a specific response (e.g., inhibition or suppression of the Th2 response) or of certain molecules. PHARMACEUTICAL COMPOSITIONS [00177] The invention also includes pharmaceutical compositions containing aptamer molecules that bind to IL-23 and/or IL-12. In some embodiments, the compositions are suitable for internal use and include an effective amount of a pharmacologically active compound of the invention, alone or in combination, with one or more pharmaceutically acceptable carriers. The compounds are especially useful in that they have very low, if any toxicity. [001781 Compositions of the invention can be used to treat or prevent a pathology, such as a disease or disorder, or alleviate the symptoms of such disease or disorder in a patient. For example, compositions of the present invention can be used to treat or prevent a pathology associated with IL-23 and/or IL- 12 cytokines, including inflammatory and autoimmune related diseases, Type I Diabetes, bone resorption in osteoporosis, and cancer. [001791 Compositions of the invention are useful for administration to a subject suffering from, or predisposed to, a disease or disorder which is related to or derived from a target to which the aptamers of the invention specifically bind. Compositions of the invention can be used in a method for treating a patient or subject having a pathology. The method involves administering to the patient or subject an aptamer or a composition comprising aptamers that bind to IL-23 and/or IL-12 involved with the pathology, so that binding of the aptamer to the IL-23 and/or IL-12 alters the biological function of the target, thereby treating the pathology. 52 WO 2007/035922 PCT/US2006/037276 [00180] The patient or subject having a pathology, i.e., the patient or subject treated by the methods of this invention, can be a vertebrate, more particularly a manmal, or more particularly a human. [00181] In practice, the aptamers or their phannaceutically acceptable salts, are administered in amounts which will be sufficient to exert their desired biological activity, e.g., inhibiting the binding of the IL-23 and/or IL- 12 to its receptor. [00182] One aspect of the invention comprises an aptamer composition of the invention in combination with other treatments for inflammatory and autoimmune diseases, cancer, and other related disorders. The aptamer composition of the invention may contain, for example, more than one aptamer. In some examples, an aptamer composition of the invention, containing one or more compounds of the invention, is administered in combination with another useful composition such as an anti-inflammatory agent, an innnunosuppressant, an antiviral agent, or the like. Furthermore, the compounds of the invention may be administered in combination with a cytotoxic, cytostatic, or chemotherapeutic agent such as an alkylating agent, anti-metabolite, mitotic inhibitor or cytotoxic antibiotic, as described above. In general, the currently available dosage forms of the known therapeutic agents for use in such combinations will be suitable. [00183] "Combination therapy" (or "co-therapy") includes the administration of an aptamer composition of the invention and at least a second agent as part of a specific treatment regimen intended to provide the beneficial effect from the co-action of these therapeutic agents. The beneficial effect of the combination includes, but is not limited to, pharmacokinetic or pharmacodynamic co-action resulting from the combination of therapeutic agents. Administration of these therapeutic agents in combination typically is carried out over a defined time period (usually minutes, hours, days or weeks depending upon the combination selected). [00184] "Combination therapy" may, but generally is not, intended to encompass the administration of two or more of these therapeutic agents as part of separate monotherapy regimens that incidentally and arbitrarily result in the combinations of the present invention. "Combination therapy" is intended to embrace administration of these therapeutic agents in a sequential manner, that is, wherein each therapeutic agent is administered at a different time, as well as administration of these therapeutic agents, or at least two of the therapeutic agents, in a substantially simultaneous manner. Substantially simultaneous administration 53 WO 2007/035922 PCT/US2006/037276 can be accomplished, for example, by administering to the subject a single capsule having a fixed ratio of each therapeutic agent or in multiple, single capsules for each of the therapeutic agents. [00185] Sequential or substantially simultaneous administration of each therapeutic agent can be effected by any appropriate route including, but not limited to, topical routes, oral routes, intravenous routes, intramuscular routes, and direct absorption through mucous membrane tissues. The therapeutic agents can be administered by the same route or by different routes. For example, a first therapeutic agent of the combination selected may be administered by injection while the other therapeutic agents of the combination may be administered topically. [00186] Alternatively, for example, all therapeutic agents may be administered topically or all therapeutic agents may be administered by injection. The sequence in which the therapeutic agents are administered is not narrowly critical unless noted otherwise. "Combination therapy" also can embrace the administration of the therapeutic agents as described above in further combination with other biologically active ingredients. Where the combination therapy further comprises a non-drug treatment, the non-drug treatment may be conducted at any suitable time so long as a beneficial effect from the co-action of the combination of the therapeutic agents and non-drug treatment is achieved. For example, in appropriate cases, the beneficial effect is still achieved when the non-drug treatment is temporally removed from the administration of the therapeutic agents, perhaps by days or even weeks. [00187] Therapeutic or pharmacological compositions of the present invention will generally comprise an effective amount of the active component(s) of the therapy, dissolved or dispersed in a pharmaceutically acceptable medium. Pharmaceutically acceptable media or carriers include any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents and the like. The use of such media and agents for pharmaceutical active substances is well known in the art. Supplementary active ingredients can also be incorporated into the therapeutic compositions of the present invention. [00188] The preparation of pharmaceutical or pharmacological compositions will be known to those of skill in the art in light of the present disclosure. Typically, such compositions may be prepared as injectables, either as liquid solutions or suspensions; solid 54 WO 2007/035922 PCT/US2006/037276 forms suitable for solution in, or suspension in, liquid prior to injection; as tablets or other solids for oral administration; as time release capsules; or in any other fonn currently used, including eye drops, creams, lotions, salves, inhalants and the like. The use of sterile formulations, such as saline-based washes, by surgeons, physicians or health care workers to treat a particular area in the operating field may also be particularly useful. Compositions may also be delivered via microdevice, microparticle or sponge. [001891 Upon formulation, therapeutics will be administered in a manner compatible with the dosage formulation, and in such amount as is pharmacologically effective. The formulations are easily administered in a variety of dosage fonns, such as the type of injectable solutions described above, but drug release capsules and the like can also be employed. [00190] In this context, the quantity of active ingredient and volume of composition to be administered depends on the host animal to be treated. Precise amounts of active compound required for administration depend on the judgment of the practitioner and are peculiar to each individual. [00191] A minimal volume of a composition required to disperse the active compounds is typically utilized. Suitable regimes for administration are also variable, but would be typified by initially administering the compound and monitoring the results and then giving further controlled doses at further intervals. [00192] For instance, for oral administration in the form of a tablet or capsule (e.g., a gelatin capsule), the active drug component can be combined with an oral, non-toxic, phannaceutically acceptable inert carrier such as ethanol, glycerol, water and the like. Moreover, when desired or necessary, suitable binders, lubricants, disintegrating agents, and coloring agents can also be incorporated into the mixture. Suitable binders include starch, magnesium aluminum silicate, starch paste, gelatin, methylcellulose, sodium carboxymethylcellulose and/or polyvinylpyrrolidone, natural sugars such as glucose or beta lactose, corn sweeteners, natural and synthetic gums such as acacia, tragacanth or sodium alginate, polyethylene glycol, waxes, and the like. Lubricants used in these dosage forms include sodium oleate, sodium stearate, magnesium stearate, sodium benzoate, sodium acetate, sodium chloride, silica, talcum, stearic acid, its magnesium or calcium salt and/or polyethyleneglycol, and the like. Disintegrators include, without limitation, starch, methyl cellulose, agar, bentonite, xanthan gum starches, agar, alginic acid or its sodium salt, or 55 WO 2007/035922 PCT/US2006/037276 effervescent mixtures, and the like. Diluents, include, e.g., lactose, dextrose, sucrose, mannitol, sorbitol, cellulose and/or glycine. [00193] The compounds of the invention can also be administered in such oral dosage forms as timed release and sustained release tablets or capsules, pills, powders, granules, elixirs, tinctures, suspensions, syrups and emulsions. Suppositories are advantageously prepared from fatty emulsions or suspensions. [00194] The phannaceutical compositions may be sterilized and/or contain adjuvants, such as preserving, stabilizing, wetting or emulsifying agents, solution promoters, salts for regulating the osmotic pressure and/or buffers. In addition, they may also contain other therapeutically valuable substances. The compositions are prepared according to conventional mixing, granulating, or coating methods, and typically contain about 0.1% to 75%, preferably about 1% to 50%, of the active ingredient. [00195] Liquid, particularly injectable compositions can, for example, be prepared by dissolving, dispersing, etc. The active compound is dissolved in or mixed with a pharmaceutically pure solvent such as, for example, water, saline, aqueous dextrose, glycerol, ethanol, and the like, to thereby form the injectable solution or suspension. Additionally, solid forms suitable for dissolving in liquid prior to injection can be formulated. [00196] The compounds of the present invention can be administered in intravenous (both bolus and infusion), intraperitoneal, subcutaneous or intramuscular form, all using forms well known to those of ordinary skill in the pharmaceutical arts. Injectables can be prepared in conventional forms, either as liquid solutions or suspensions. [00197] Parenteral injectable administration is generally used for subcutaneous, intramuscular or intravenous injections and infusions. Additionally, one approach for parenteral administration employs the implantation of a slow-release or sustained-released systems, which assures that a constant level of dosage is maintained, according to U.S. Pat. No. 3,710,795, incorporated herein by reference. [00198] Furthermore, preferred compounds for the present invention can be administered in intranasal fonn via topical use of suitable intranasal vehicles, inhalants, or via transdennal routes, using those forms of transdermal skin patches well known to those of ordinary skill in that art. To be administered in the form of a transdermal delivery system, 56 WO 2007/035922 PCT/US2006/037276 the dosage administration will, of course, be continuous rather than intennittent throughout the dosage regimen. Other preferred topical preparations include creams, ointments, lotions, aerosol sprays and gels, wherein the concentration of active ingredient would typically range from 0.01% to 15%, w/w or w/v. [00199] For solid compositions, excipients include pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharin, talcum, cellulose, glucose, sucrose, magnesium carbonate, and the like. The active compound defined above, may be also fonnulated as suppositories, using for example, polyalkylene glycols, for example, propylene glycol, as the carrier. In some embodiments, suppositories are advantageously prepared from fatty emulsions or suspensions. [00200] The compounds of the present invention can also be administered in the form of liposome delivery systems, such as small unilamellar vesicles, large unilamellar vesicles and multilamellar vesicles. Liposomes can be formed from a variety of phospholipids, containing cholesterol, stearylamine or phosphatidylcholines. In some embodiments, a film of lipid components is hydrated with an aqueous solution of drug to a fonn lipid layer encapsulating the drug, as described in U.S. Pat. No. 5,262,564. For example, the aptamer molecules described herein can be provided as a complex with a lipophilic compound or non-inununogenic, high molecular weight compound constructed using methods known in the art. An example of nucleic-acid associated complexes is provided in U.S. Patent No. 6,011,020. [002011 The compounds of the present invention may also be coupled with soluble polymers as targetable drug carriers. Such polymers can include polyvinylpyrrolidone, pyran copolymer, polyhydroxypropyl-methacrylamide-phenol, polyhydroxyethylaspanamidephenol, or polyethyleneoxidepolylysine substituted with palmitoyl residues. Furthermore, the compounds of the present invention may be coupled to a class of biodegradable polymers useful in achieving controlled release of a drug, for example, polylactic acid, polyepsilon caprolactone, polyhydroxy butyric acid, polyorthoesters, polyacetals, polydihydropyrans, polycyanoacrylates and cross-linked or amphipathic block copolymers of hydrogels. [00202] If desired, the pharmaceutical composition to be administered may also contain minor amounts of non-toxic auxiliary substances such as wetting or emulsifying agents, pH 57 WO 2007/035922 PCT/US2006/037276 buffering agents, and other substances such as for example, sodium acetate, and triethanolamine oleate. [00203] The dosage regimen utilizing the aptamers is selected in accordance with a variety of factors including type, species, age, weight, sex and medical condition of the patient; the severity of the condition to be treated; the route of administration; the renal and hepatic function of the patient; and the particular aptamer or salt thereof employed. An ordinarily skilled physician or veterinarian can readily determine and prescribe the effective amount of the drug required to prevent, counter or arrest the progress of the condition. [00204] Oral dosages of the present invention, when used for the indicated effects, will range between about 0.05 to 7500 mg/day orally. The compositions are preferably provided in the form of scored tablets containing 0.5, 1.0, 2.5, 5.0, 10.0, 15.0, 25.0, 50.0, 100.0, 250.0, 500.0 and 1000.0 mg of active ingredient. Infused dosages, intranasal dosages and transdernal dosages will range between 0.05 to 7500 mg/day. Subcutaneous, intravenous and intraperitoneal dosages will range between 0.05 to 3800 mg/day. [00205] Effective plasma levels of the compounds of the present invention range from 0.002 mg/mL to 50 mg/mL. [002061 Compounds of the present invention may be administered in a single daily dose, or the total daily dosage may be administered in divided doses of two, three or four times daily. MODULATION OF PHARMACOKINETICS AND BIODISTRIBUTION OF APTAMER THERAPEUTICS [00207] It is important that the phannacokinetic properties for all oligonucleotide-based therapeutics, including aptamers, be tailored to match the desired pharmaceutical application. While aptamers directed against extracellular targets do not suffer from difficulties associated with intracellular delivery (as is the case with antisense and RNAi based therapeutics), such aptamers must still be able to be distributed to target organs and tissues, and remain in the body (unmodified) for a period of time consistent with the desired dosing regimen. [00208] Thus, the present invention provides materials and methods to affect the pharmacokinetics of aptamer compositions, and, in particular, the ability to tune aptamer 58 WO 2007/035922 PCT/US2006/037276 pharmacokinetics. The tunability of (i.e., the ability to modulate) aptamer pharmacokinetics is achieved through conjugation of modifying moieties (e.g., PEG polymers) to the aptamer and/or the incorporation of modified nucleotides (e.g., 2'-fluoro or 2'-0-methyl) to alter the chemical composition of the nucleic acid. The ability to tune aptamer pharmacokinetics is used in the improvement of existing therapeutic applications, or alternatively, in the development of new therapeutic applications. For example, in some therapeutic applications, e.g., in anti-neoplastic or acute care settings where rapid drug clearance or turn-off may be desired, it is desirable to decrease the residence times of aptamers in the circulation. Alternatively, in other therapeutic applications, e.g., maintenance therapies where systemic circulation of a therapeutic is desired, it may be desirable to increase the residence times of aptamers in circulation. [002091 In addition, the tunability of aptamer phannacokinetics is used to modify the biodistribution of an aptamer therapeutic in a subject. For example, in some therapeutic applications, it may be desirable to alter the biodistribution of an aptamer therapeutic in an effort to target a particular type of tissue or a specific organ (or set of organs). In these applications, the aptamer therapeutic preferentially accumulates in a specific tissue or organ(s). In other therapeutic applications, it may be desirable to target tissues displaying a cellular marker or a symptom associated with a given disease, cellular injury or other abnormal pathology, such that the aptamer therapeutic preferentially accumulates in the affected tissue. For example, as described in copending provisional application United States Serial No. 60/550790, filed on March 5, 2004, and entitled "Controlled Modulation of the Pharmacokinetics and Biodistribution of Aptamer Therapeutics", and in the non provisional application United States Serial No. 10/---,---, filed on March 7, 2005, also entitled "Controlled Modulation of the Pharmacokinetics and Biodistribution of Aptamer Therapeutics", PEGylation of an aptamer therapeutic (e.g., PEGylation with a 20 kDa PEG polymer) is used to target inflamed tissues, such that the PEGylated aptamer therapeutic preferentially accumulates in inflamed tissue. [002101 To determine the pharmacokinetic and biodistribution profiles of aptamer therapeutics (e.g., aptamer conjugates or aptamers having altered chemistries, such as modified nucleotides) a variety of parameters are monitored. Such parameters include, for example, the half-life (t 1

/

2 ), the plasma clearance (Cl), the volume of distribution (Vss), the area under the concentration-time curve (AUC), maximum observed serum or plasma concentration (Cma), and the mean residence time (MRT) of an aptamer composition. As 59 WO 2007/035922 PCT/US2006/037276 used herein, the term "AUC" refers to the area under the plot of the plasma concentration of an aptamer therapeutic versus the time after aptamer administration. The AUC value is used to estimate the bioavailability (i.e., the percentage of administered aptamer therapeutic in the circulation after aptamer administration) and/or total clearance (C1) (i.e., the rate at which the aptamer therapeutic is removed from circulation) of a given aptamer therapeutic. The volume of distribution relates the plasma concentration of an aptamer therapeutic to the amount of aptamer present in the body. The larger the Vss, the more an aptamer is found outside of the plasma (i.e., the more extravasation). [00211] The present invention provides materials and methods to modulate, in a controlled manner, the pharmacokinetics and biodistribution of stabilized aptamer compositions in vivo by conjugating an aptamer to a modulating moiety such as a small molecule, peptide, or polymer terminal group, or by incorporating modified nucleotides into an aptamer. As described herein, conjugation of a modifying moiety and/or altering nucleotide(s) chemical composition alters fundamental aspects of aptamer residence time in circulation and distribution to tissues. [00212] In addition to clearance by nucleases, oligonucleotide therapeutics are subject to elimination via renal filtration. As such, a nuclease-resistant oligonucleotide administered intravenously typically exhibits an in vivo half-life of <10 min, unless filtration can be blocked. This can be accomplished by either facilitating rapid distribution out of the blood stream into tissues or by increasing the apparent molecular weight of the oligonucleotide above the effective size cut-off for the glomerulus. Conjugation of small therapeutics to a PEG polymer (PEGylation), described below, can dramatically lengthen residence times of aptamers in circulation, thereby decreasing dosing frequency and enhancing effectiveness against vascular targets. [002131 Aptamers can be conjugated to a variety of modifying moieties, such as high molecular weight polymers, e.g., PEG; peptides, e.g., Tat (a 13-amino acid fragment of the HIV Tat protein (Vives, et al., (1997), J. Biol. Chem. 272(25): 16010-7)), Ant (a 16-amino acid sequence derived from the third helix of the Drosophila antennapedia homeotic protein (Pietersz, et al., (2001), Vaccine 19(11-12): 1397-405)) and Arg 7 (a short, positively charged cell-penneating peptides composed of polyarginine (Arg 7 ) (Rothbard, et al., (2000), Nat. Med. 6(11): 1253-7; Rothbard, J et al., (2002), J. Med. Chem. 45(17): 3612-8)); and small molecules, e.g., lipophilic compounds such as cholesterol. Among the various 60 WO 2007/035922 PCT/US2006/037276 conjugates described herein, in vivo properties of aptamers are altered most profoundly by complexation with PEG groups. For example, complexation of a mixed 2'F and 2'-OMe modified aptamer therapeutic with a 20 kDa PEG polymer hinders renal filtration and promotes aptamer distribution to both healthy and inflamed tissues. Furthermore, the 20 kDa PEG polymer-aptamer conjugate proves nearly as effective as a 40 kDa PEG polymer in preventing renal filtration of aptamers. While one effect of PEGylation is on aptamer clearance, the prolonged systemic exposure afforded by presence of the 20 kDa moiety also facilitates distribution of aptamer to tissues, particularly those of highly perfused organs and those at the site of inflammation. The aptamer-20 kDa PEG polymer conjugate directs aptamer distribution to the site of inflammation, such that the PEGylated aptamer preferentially accumulates in inflamed tissue. In some instances, the 20 kDa PEGylated aptainer conjugate is able to access the interior of cells, such as, for example, kidney cells. [00214] Modified nucleotides can also be used to modulate the plasma clearance of aptamers. For example, an unconjugated aptamer which incorporates both 2'-F and 2'-OMe stabilizing chemistries, which is typical of current generation aptamers as it exhibits a high degree of nuclease stability in vitro and in vivo, displays rapid loss from plasma (i.e., rapid plasma clearance) and a rapid distribution into tissues, primarily into the kidney, when compared to unmodified aptamer. PEG-DERIVATIZED NUCLEIC ACIDS [00215] As described above, derivatization of nucleic acids with high molecular weight non-immunogenic polymers has the potential to alter the pharmacokinetic and pharmacodynamic properties of nucleic acids making them more effective therapeutic agents. Favorable changes in activity can include increased resistance to degradation by nucleases, decreased filtration through the kidneys, decreased exposure to the immune system, and altered distribution of the therapeutic through the body. [002161 The aptamer compositions of the invention may be derivatized with polyalkylene glycol ("PAG") moieties. Examples of PAG-derivatized nucleic acids are found in United States Patent Application Ser. No. 10/718,833, filed on November 21, 2003, which is herein incorporated by reference in its entirety. Typical polymers used in the invention include polyethylene glycol ("PEG"), also known as polyethylene oxide ("PEO") and polypropylene glycol (including poly isopropylene glycol). Additionally, random or block copolymers of different alkylene oxides (e.g., ethylene oxide and propylene oxide) can be 61 WO 2007/035922 PCT/US2006/037276 used in many applications. In its most common fonn, a polyalkylene glycol, such as PEG, is a linear polymer terminated at each end with hydroxyl groups: HO-CH 2

CH

2 0

(CH

2

CH

2 0),,-CH 2

CH

2 -OH. This polymer, alpha-, omega-dihydroxylpolyethylene glycol, can also be represented as HO-PEG-OH, where it is understood that the -PEG- symbol represents the following structural unit: -CH 2

CH

2 0-(CH 2

CH

2

O),-CH

2

CH

2 - where n typically ranges from about 4 to about 10,000. [00217] As shown, the PEG molecule is di-functional and is sometimes referred to as "PEG diol." The terminal portions of the PEG molecule are relatively non-reactive hydroxyl moieties, the -OH groups, that can be activated, or converted to functional moieties, for attachment of the PEG to other compounds at reactive sites on the compound. Such activated PEG diols are referred to herein as bi-activated PEGs. For example, the terminal moieties of PEG diol have been functionalized as active carbonate ester for selective reaction with amino moieties by substitution of the relatively non-reactive hydroxyl moieties, -OH, with succinimidyl active ester moieties from N-hydroxy succinimide. [00218] In many applications, it is desirable to cap the PEG molecule on one end with an essentially non-reactive moiety so that the PEG molecule is mono-functional (or mono activated). In the case of protein therapeutics which generally display multiple reaction sites for activated PEGs, bi-functional activated PEGs lead to extensive cross-linking, yielding poorly functional aggregates. To generate mono-activated PEGs, one hydroxyl moiety on the terminus of the PEG diol molecule typically is substituted with non-reactive methoxy end moiety, -OCH 3 . The other, un-capped terminus of the PEG molecule typically is converted to a reactive end moiety that can be activated for attachment at a reactive site on a surface or a molecule such as a protein. [002191 PAGs are polymers which typically have the properties of solubility in water and in many organic solvents, lack of toxicity, and lack of immunogenicity. One use of PAGs is to covalently attach the polymer to insoluble molecules to make the resulting PAG molecule "conjugate" soluble. For example, it has been shown that the water-insoluble drug paclitaxel, when coupled to PEG, becomes water-soluble. Greenwald, et aL, J. Org. Chem., 60:331-336 (1995). PAG conjugates are often used not only to enhance solubility and stability but also to prolong the blood circulation half-life of molecules. 62 WO 2007/035922 PCT/US2006/037276 [00220] Polyalkylated compounds of the invention are typically between 5 and 80 kDa in size however any size can be used, the choice dependent on the aptamer and application. Other PAG compounds of the invention are between 10 and 80 kDa in size. Still other PAG compounds of the invention are between 10 and 60 kDa in size. For example, a PAG polymer may be at least 10, 20, 30, 40, 50, 60, or 80 kDa in size. Such polymers can be linear or branched. In some embodiments the polymers are PEG. In some embodiment the polymers are branched PEG. In still other embodiments the polymers are 40kDa branched PEG as depicted in Figure 4. In some embodiments the 40 kDa branched PEG is attached to the 5' end of the aptamer as depicted in Figure 5. [00221] In contrast to biologically-expressed protein therapeutics, nucleic acid therapeutics are typically chemically synthesized from activated monomer nucleotides. PEG-nucleic acid conjugates may be prepared by incorporating the PEG using the same iterative monomer synthesis. For example, PEGs activated by conversion to a phosphoramidite form can be incorporated into solid-phase oligonucleotide synthesis. Alternatively, oligonucleotide synthesis can be completed with site-specific incorporation of a reactive PEG attachment site. Most commonly this has been accomplished by addition of a free primary amine at the 5'-terminus (incorporated using a modifier phosphoramidite in the last coupling step of solid phase synthesis). Using this approach, a reactive PEG (e.g., one which is activated so that it will react and fonn a bond with an amine) is combined with the purified oligonucleotide and the coupling reaction is carried out in solution. [002221 The ability of PEG conjugation to alter the biodistribution of a therapeutic is related to a number of factors including the apparent size (e.g., as measured in terms of hydrodynamic radius) of the conjugate. Larger conjugates (>10 kDa) are known to more effectively block filtration via the kidney and to consequently increase the serum half-life of small macromolecules (e.g., peptides, antisense oligonucleotides). The ability of PEG conjugates to block filtration has been shown to increase with PEG size up to approximately 50 kDa (further increases have minimal beneficial effect as half life becomes defined by macrophage-mediated metabolism rather than elimination via the kidneys). [00223] Production of high molecular weight PEGs (>10 kDa) can be difficult, inefficient, and expensive. As a route towards the synthesis of high molecular weight PEG nucleic acid conjugates, previous work has been focused towards the generation of higher molecular weight activated PEGs. One method for generating such molecules involves the 63 WO 2007/035922 PCT/US2006/037276 formation of a branched activated PEG in which two or more PEGs are attached to a central core carrying the activated group. The terminal portions of these higher molecular weight PEG molecules, i.e., the relatively non-reactive hydroxyl (-OH) moieties, can be activated, or converted to functional moieties, for attachment of one or more of the PEGs to other compounds at reactive sites on the compound. Branched activated PEGs will have more than two termini, and in cases where two or more tennini have been activated, such activated higher molecular weight PEG molecules are referred to herein as, multi-activated PEGs. In some cases, not all termini in a branch PEG molecule are activated. In cases where any two termini of a branch PEG molecule are activated, such PEG molecules are referred to as bi-activated PEGs. In some cases where only one terminus in a branch PEG molecule is activated, such PEG molecules are referred to as mono-activated. As an example of this approach, activated PEG prepared by the attachment of two monomethoxy PEGs to a lysine core which is subsequently activated for reaction has been described (Harris et al., Nature, vol.2: 214-221, 2003). [00224] The present invention provides another cost effective route to the synthesis of high molecular weight PEG-nucleic acid (preferably, aptamer) conjugates including multiply PEGylated nucleic acids. The present invention also encompasses PEG-linked multimeric oligonucleotides, e.g., dimerized aptamers. The present invention also relates to high molecular weight compositions where a PEG stabilizing moiety is a linker which separates different portions of an aptamer, e.g., the PEG is conjugated within a single aptamer sequence, such that the linear arrangement of the high molecular weight aptamer composition is, e.g., nucleic acid - PEG - nucleic acid (- PEG - nucleic acid), where n is greater than or equal to 1. [002251 High molecular weight compositions of the invention include those having a molecular weight of at least 10 kDa. Compositions typically have a molecular weight between 10 and 80 kDa in size. High molecular weight compositions of the invention are at least 10, 20, 30, 40, 50, 60, or 80 kDa in size. [00226] A stabilizing moiety is a molecule, or portion of a molecule, which improves pharmacokinetic and phannacodynamic properties of the high molecular weight aptamer compositions of the invention. In some cases, a stabilizing moiety is a molecule or portion of a molecule which brings two or more aptamers, or aptamer domains, into proximity, or provides decreased overall rotational freedom of the high molecular weight aptamer 64 WO 2007/035922 PCT/US2006/037276 compositions of the invention. A stabilizing moiety can be a polyalkylene glycol, such a polyethylene glycol, which can be linear or branched, a homopolymer or a heteropolymer. Other stabilizing moieties include polymers such as peptide nucleic acids (PNA). Oligonucleotides can also be stabilizing moieties; such oligonucleotides can include modified nucleotides, and/or modified linkages, such as phosphorothioates. A stabilizing moiety can be an integral part of an aptamer composition, i.e., it is covalently bonded to the aptamer. [002271 Compositions of the invention include high molecular weight aptamer compositions in which two or more nucleic acid moieties are covalently conjugated to at least one polyalkylene glycol moiety. The polyalkylene glycol moieties serve as stabilizing moieties. In compositions where a polyalkylene glycol moiety is covalently bound at either end to an aptamer, such that the polyalkylene glycol joins the nucleic acid moieties together in one molecule, the polyalkylene glycol is said to be a linking moiety. In such compositions, the primary structure of the covalent molecule includes the linear arrangement nucleic acid-PAG-nucleic acid. One example is a composition having the primary structure nucleic acid-PEG-nucleic acid. Another example is a linear arrangement of: nucleic acid - PEG - nucleic acid - PEG - nucleic acid. [002281 To produce the nucleic acid-PEG-nucleic acid conjugate, the nucleic acid is originally synthesized such that it bears a single reactive site (e.g., it is mono-activated). In a preferred embodiment, this reactive site is an amino group introduced at the 5'-tenninus by addition of a modifier phosphoramidite as the last step in solid phase synthesis of the oligonucleotide. Following deprotection and purification of the modified oligonucleotide, it is reconstituted at high concentration in a solution that minimizes spontaneous hydrolysis of the activated PEG. In a preferred embodiment, the concentration of oligonucleotide is 1 mM and the reconstituted solution contains 200 mM NaHCO 3 -buffer, pH 8.3. Synthesis of the conjugate is initiated by slow, step-wise addition of highly purified bi-functional PEG. In a preferred embodiment, the PEG diol is activated at both ends (bi-activated) by derivatization with succinimidyl propionate. Following reaction, the PEG-nucleic acid conjugate is purified by gel electrophoresis or liquid chromatography to separate fully-, partially-, and un-conjugated species. Multiple PAG molecules concatenated (e.g., as random or block copolymers) or smaller PAG chains can be linked to achieve various lengths (or molecular weights). Non-PAG linkers can be used between PAG chains of varying lengths. 65 WO 2007/035922 PCT/US2006/037276 [00229] The 2'-O-methyl, 2'-fluoro and other modified nucleotide modifications stabilize the aptamer against nucleases and increase its half life in vivo. The 3'-3'-dT cap also increases exonuclease resistance. See, e.g., U.S. Patents 5,674,685; 5,668,264; 6,207,816; and 6,229,002, each of which is incorporated by reference herein in its entirety. PAG-DERIVATIZATION OF A REACTIVE NUCLEIC ACID [00230] High molecular weight PAG-nucleic acid-PAG conjugates can be prepared by reaction of a mono-ftnctional activated PEG with a nucleic acid containing more than one reactive site. In one embodiment, the nucleic acid is bi-reactive, or bi-activated, and contains two reactive sites: a 5'-amino group and a 3'-amino group introduced into the oligonucleotide through conventional phosphoramidite synthesis, for example: 3'-5'-di PEGylation as illustrated in Figure 6. In alternative embodiments, reactive sites can be introduced at internal positions, using for example, the 5-position of pyrimidines, the 8 position of purines, or the 2 '-position of ribose as sites for attachment of primary amines. In such embodiments, the nucleic acid can have several activated or reactive sites and is said to be multiply activated. Following synthesis and purification, the modified oligonucleotide is combined with the mono-activated PEG under conditions that promote selective reaction with the oligonucleotide reactive sites while minimizing spontaneous hydrolysis. In the preferred embodiment, monomethoxy-PEG is activated with succinimidyl propionate and the coupled reaction is carried out at pH 8.3. To drive synthesis of the bi-substituted PEG, stoichiometric excess PEG is provided relative to the oligonucleotide. Following reaction, the PEG-nucleic acid conjugate is purified by gel electrophoresis or liquid chromatography to separate fully, partially, and un-conjugated species. [00231] The linking domains can also have one or more polyalkylene glycol moieties attached thereto. Such PAGs can be of varying lengths and may be used in appropriate combinations to achieve the desired molecular weight of the composition. [002321 The effect of a particular linker can be influenced by both its chemical composition and length. A linker that is too long, too short, or forms unfavorable steric and/or ionic interactions with the IL-23 and/or IL-12 will preclude the formation of complex between the aptamer and IL-23 and/or IL-1 2. A linker, which is longer than necessary to span the distance between nucleic acids, may reduce binding stability by diminishing the 66 WO 2007/035922 PCT/US2006/037276 effective concentration of the ligand. Thus, it is often necessary to optimize linker compositions and lengths in order to maximize the affinity of an aptamer to a target. [002331 All publications and patent documents cited herein are incorporated herein by reference as if each such publication or document was specifically and individually indicated to be incorporated herein by reference. Citation of publications and patent documents is not intended as an admission that any is pertinent prior art, nor does it constitute any admission as to the contents or date of the same. The invention having now been described by way of written description, those of skill in the art will recognize that the invention can be practiced in a variety of embodiments and that the foregoing description and examples below are for purposes of illustration and not limitation of the claims that follow. EXAMPLES EXAMPLE 1: APTAMER SELECTION AND SEQUENCES IL-23 Aptamer Selection [00234] Several SELEX m strategies were employed to generate ligands with a variety of specificities for IL-23 and IL-12. One scheme, designed to produce aptamers specific for IL-23 vs. IL-12, included IL-12 in a negative selection step to eliminate aptamers that recognize the common subunit and select for aptamers specific to IL-23. A separate SELEX " scheme in which IL-23 and IL- 12 were alternated every other round elicited aptamers that recognized the common subunit and therefore recognized both proteins. In Examples IA and IE, selections were done with 2'-OH purine and 2'-F pyrimidine (rRfY) containing pools. Clones from these selections were optimized based on their binding affinity and efficacy in blocking IL-23 activity in a cell based assay. In addition, selections with 2'-OMe nucleotide containing pools, i.e., rRmY (2'-OH A and G, and 2'-OMe C and U), rGmH (2'-OH G and 2'-OMe C, U, A), and dRmY (deoxy A and G, and 2'-OMe C and U) are described in Examples IB, IC, and 1D below. 67 WO 2007/035922 PCT/US2006/037276 EXAMPLE 1A: Selections against human IL-23 with 2'-Fluoro pyrimidines containing pools (rRfY) [002351 Three selections were performed to identify aptamers to human ("h")-IL-23 using a pool consisting of 2'-OH purine (ribo-purines) and 2'-F pyrimidine nucleotides (rRfY conditions). The first selection (h-IL-23) was a direct selection against h-IL-23, which is comprised of p19 and p40 domains. The second selection (X-IL-23) utilized h-IL 23 and h-IL-12 in alternating rounds to drive selection of aptamers to the common subunit between the two proteins, p40. In the third selection (PN-IL-23), h-IL- 12 was included in the negative selection step to drive enrichment of aptamers binding to the subdomain unique to h-IL-23, p19. As described below, the starting material for this third selection, i.e., the PN-IL-23 selection was a portion of the pool from the h-IL-23 selection, separated from the remainder of the h-IL-23 pool after two rounds of selection against h-IL-23 protein. All three selection strategies yielded aptamers to h-IL-23. Several aptamers are highly specific for h-IL-23, several show cross reactivity between h-IL-23 and h-IL-12, and one is more specific for h-IL- 12 vs. h-IL-23. [002361 Round 1 of the h-IL-23 and the PN-IL-23 selection began with incubation of 2x1014 molecules of 2'F pyrimidine modified ARC 212 pool (SEQ ID NO 8) (5'gggaaaagegaaucauacacaaga-N40-gcuccgccagagaccaaccgagaa3'), including a spike of o P ATP body labeled pool, with 100 pmoles of IL-23 protein (R&D, Minneapolis, MN) in a final volume of 100 ptL for lhr at room temperature. The series of N's in the template (SEQ ID NO 8) can be any combination of nucleotides and gives rise to the unique sequence region of the resulting aptamers. [002371 After Round 2, the pool was divided into two equal portions, one portion was used for subsequent rounds (i.e., Rounds 3-12) of the h-IL-23 selection and the other portion was used for the subsequent rounds (i.e., Rounds 3-11) of the PN-IL-23 selection. Round 1 of the X-IL-23 selection was conducted similarly, except the pool RNA was incubated with 50 pmoles of h-IL-23 and 50 poles of h-IL-12. [00238] All selections were performed in IX SHMCK buffer, pH 7.4 (20 mM Hepes pH 7.4, 120 mM NaCl, 5 mM KCl, 1 mM MgCl 2 , 1 mM CaCl 2 ). RNA:h-IL-23 complexes and free RNA molecules were separated using 0.45 pim nitrocellulose spin columns from Schleicher & Schuell (Keene, NH). The columns were pre-washed with 1 iL 1X SHMCK, and then the RNA:protein containing solutions were added to the columns and spun in a 68 WO 2007/035922 PCT/US2006/037276 centrifuge at 1500 g for 2 minutes. Buffer washes were performed to remove nonspecific binders from the filters (Round 1, 2 x 500 pL 1X SHMCK; in later rounds, more stringent washes of increased number and volume to enrich for specific binders), then the RNA:protein complexes attached to the filters were eluted with 2 x 200 pL washes (2 x 100 pL washes in later rounds) of elution buffer (7 M urea, 100 mM sodium acetate, 3 mM EDTA, pre-heated to 95'C). The eluted RNA was phenol:chloroform extracted, then precipitated (40 tg glycogen, 1 volume isopropanol). The RNA was reverse transcribed with the Thermoscriptm1 RT-PCR system (Invitrogen, Carlsbad, CA) according to the manufacturer's instructions, using the 3' primer 5'ttctcggttggtctctggcggage 3' (SEQ ID NO 10), followed by amplification by PCR (20 mM Tris pH 8.4, 50 mM KCl, 2 mM MgC 2 , 0.5 pM of 5' primer 5'taatacgactcactatagggaaaagcgaatcatacacaaga 3' (SEQ ID NO 9), 0.5 piM of 3' primer (SEQ ID NO 10), 0.5 mM each dNTP, 0.05 units/pL Taq polyinerase (New England Biolabs, Beverly, MA)). PCR reactions were done under the following cycling conditions: a) 94'C for 30 seconds; b) 55'C for 30 seconds; c) 72'C for 30 seconds. The cycles were repeated until sufficient PCR product was generated. The minimum number of cycles required to generate sufficient PCR product is reported in Tables 1-3 below as the "PCR Threshold". [00239] The PCR templates were purified using the QlAquick PCR purification kit (Qiagen, Valencia, CA). Templates were transcribed using a2P ATP body labeling overnight at 37 0 C (4% PEG-8000, 40 mM Tris pH 8.0, 12 mM MgCl 2 , 1 mM spenmidine, 0.002 % Triton X-1 00, 3 mM 2'OH purines, 3 mM 2'F pyrimidines, 25 mM DTT, 0.0025 units/pL inorganic pyrophosphatase, 2 p.g/mL T7 Y639F single mutant RNA polymerase, 5 LCi a 2 P ATP). The reactions were desalted using Bio Spin columns (Bio-Rad, Hercules, CA) according to the manufacturer's instructions. [00240] Subsequent rounds of all three selections were repeated using the same method as for Round 1, except for the changes indicated in Tables 1-3. Prior to incubation with protein target, the pool RNA was passed through a 0.45 micron nitrocellulose filter column to remove filter binding sequences, then the filtrate was carried on into the positive selection step. In alternating rounds the pool RNA was gel purified. Transcription reactions were quenched with 50 mM EDTA and ethanol precipitated then purified on a 1.5 mm denaturing polyacrylamide gel (8 M urea, 10% acrylamide; 19:1 acrylamide:bisacrylamide). Pool RNA was removed from the gel by electroelution in an Elutrap@ apparatus (Schleicher and 69 WO 2007/035922 PCT/US2006/037276 Schuell, Keene, NH) at 225V for 1 hour in 1X TBE (90 mM Tris, 90 mM boric acid, 0.2 mM EDTA). The eluted material was precipitated by the addition of 300 mM sodium acetate and 2.5 volumes of ethanol. [00241] The RNA remained in excess of the protein throughout the selections (-1 -2 ptM RNA). The protein concentration was 1 pLM for the first 2 rounds, and then was dropped to varying lower concentrations based on the particular selection. Competitor tRNA was added to the binding reactions at 0.1 mg/mL starting at Round 3 or 4, depending on the selection. A total of 11-12 rounds were completed, with binding assays performed at select rounds. Tables 1-3 below contains the selection details used for the rRfY selections using the h-IL-23, X-IL-23, and PN-IL-23 selection strategies; including pool RNA concentration, protein concentration, and tRNA concentration used for each round. Elution values (ratio of CPM values of protein-bound RNA versus total RNA flowing through the filter colun) along with dot blot binding assays were used to monitor selection progress. [00242] Table 1. Conditions used for h-IL-23 Selection RNA pool protein tRNA Round conc protein conc cone PCR # (pM) type (pM) (mg/mL) neg %elution Threshold 1 3.3 IL-23 1 0 none 4.38 10 2 -1 IL-23 1 0 NC 0.85 10 3 0.8 IL-23 0.75 0 NC 10.9 8 4 ~1 IL-23 0.5 0.1 NC 0.53 8 5 1 IL-23 0.1 0.1 NC 1.72 11 6 ~1 IL-23 0.1 0.1 NC 0.11 12 7 1 IL-23 0.1 0.1 NC 1.15 8 8 -0.5 IL-23 0.05 0.1 NC 0.12 11 9 0.5 IL-23 0.05 0.1 NC 3.54 8 10 -0.5 IL-23 0.05 0.1 NC 0.18 12 11 0.5 IL-23 0.025 0.1 NC 1.09 12 12 -0.5 IL-23 0.025 0.1 NC 0.07 12 70 WO 2007/035922 PCT/US2006/037276 [00243] Table 2. Conditions used for X-IL-23 Selection RNA pool protein tRNA Round cone protein cone cone PCR # (PM) type (pM) (mg/mL) neg %elution Threshold IL-23/ 0.5 1 3.3 IL-12 each 0 none 3.15 10 IL-23/ 0.5 NC 2 ~1 IL-12 each 0 0.56 10 3 0.8 IL-12 0.75 0 NC 0.58 13 4 ~1 IL-23 0.75 0.1 NC 0.37 8 5 1 IL-12 0.5 0.1 NC 0.38 11 6 - 1 IL-23 0.1 0.1 NC 0.08 12 7 1 IL-12 0.1 0.1 NC 0.50 9 8 -0.5 IL-23 0.05 0.1 NC 0.10 11 9 0.5 IL-12 0.05 0.1 NC 0.83 11 10 ~0.5 IL-23 0.05 0.1 NC 0.17 8 11 0.5 IL-12 0.025 0.1 NC 0.91 12 12 ~0.5 IL-23 0.025 0.1 NC 0.05 12 [002441 Table 3. Conditions used for PN-IL-23 neg RNA tRNA

IL

pool protein cone 12 PCR Round cone protein cone (mg/ cone %elutio Thres # (pM) type (pM) mL) neg (pM) n hold 1 3.3 IL-23 1 0 none 0 4.38 10 2 ~1 IL-23 1 0 NC 0 0.85 10 3 0.8 IL-23 0.75 0.1 NC/IL-12 0.75 1.15 10 4 -1 IL-23 0.75 0.1 NC/IL-12 0.75 0.59 10 5 0.7 IL-23 0.5 0.1 NC/IL-12 0.5 4.19 10 6 -1 IL-23 0.1 0.1 NC/IL-12 0.5 0.05 14 7 1 IL-23 0.1 0.1 NC/IL-12 0.5 0.38 10 8 -1 IL-23 0.1 0.1 NC/IL-12 0.3 0.18 15 9 1 IL-23 0.1 0.1 NC/IL-12 0.5 2.81 8 71 WO 2007/035922 PCT/US2006/037276 10 -1 IL-23 0.05 0.1 NC/IL-12 0.5 0.21 10 11 -1 IL-23 0.05 0.1 NC/IL-12 0.5 1.35 12 [00245] Monitoring Progress of rRfY Selection. Dot blot binding assays were performed throughout the selections to monitor the protein binding affinity of the pools. Trace 32

P

labeled RNA was combined with a dilution series of h-IL-23 and incubated at room temperature for 30 minutes in 1X SHMCK (20 mM Hepes, 120 mM NaC1, 5 mM KC, 1 mM MgCl 2 , 1 mM CaCl 2 , pH 7.4) plus 0.1 mg/mL tRNA for a final volume of 20 pL. The binding reactions were analyzed by nitrocellulose filtration using a Minifold I dot-blot, 96 well vacuum filtration manifold (Schleicher & Schuell, Keene, NH). A three-layer filtration medium was used, consisting (from top to bottom) of Protran nitrocellulose (Schleicher & Schuell), Hybond-P nylon (Amersham Biosciences) and GB002 gel blot paper (Schleicher & Schuell). RNA that is bound to protein is captured on the nitrocellulose filter, whereas the non-protein bound RNA is captured on the nylon filter. The gel blot paper was included simply as a supporting medium for the other filters. Following filtration, the filter layers were separated, dried and exposed on a phosphor screen (Amersham Biosciences, Piscataway, NJ) and quantified using a Storm 860 Phosphorimager* blot imaging system (Amersham Biosciences). [00246] When a significant positive ratio of binding of RNA in the presence of h-IL-23 versus in the absence of h-IL-23 was seen, the pools were cloned using a TOPO TA cloning kit (Invitrogen, Carlsbad, CA) according to the manufacturer's instructions. For the h-IL-23 and X-IL-23 selections, the Round 8 pool templates were cloned, and 32 individual clones from each selection were assayed in a 1-point dot blot screen (+/- 75 nM h-IL-23, as well as a separate screen at +/- 75 nM h-IL-12). For the PN-IL-23 selection, the Round 10 pool was cloned and sequenced, and 8 unique clones were assayed for protein binding in a 1 point dot blot screen (+/- 200 nM h-IL-23 and a separate screen at +/- 200nM h-IL-12). Subsequently, the Round 10 PN-IL-23 pool was re-cloned for further sequences, as well as the R12 PN-IL-23 pool, and the clones were assayed for protein binding in a 1 point do blot screen (+/- 100 nM h-IL-23 or +/- 200 nM h-IL-12). For KD determination, the clone transcripts were 5'end labeled with 7 3 yP ATP. KD values were determined using a dilution series of h-IL-23 (R&D Systems, Minneapolis, MN) in the dot blot assay for all unique sequences with good +/- h-IL-23 binding ratios in the initial screens, and fitting an equation describing a 1:1 RNA:protein complex to the resulting data (fraction aptamer bound = 72 WO 2007/035922 PCT/US2006/037276 anplitude*([IL-23]/( KD + [IL-23])) (KaleidaGraph v. 3.51, Synergy Software). Results of protein binding characterization are tabulated in Table 4. Clones with high affinity to h-IL 23 were prepped and screened for functionality in cell-based assays, described in Example 3 below. [002471 Table 4. rRfY Clone binding activity (all measurements were made in the presence of 0.1 mg/mL tRNA) Round 8 h-IL-23 1-pt Screen Data SEQ Clone KDIL-23 KD IL-12 KD IL-12/KD +/-IL-23 +/-IL-12 ID NO Name (nM) (nM) IL-23 75 nM 75 nM 15 AMX86-B5 195.5 N.B. 5.79 1.01 27 AMX86-C5 80.3 399.8 4.98 6.23 2.65 13 AMX86-D5 27.4 N.B. 7.17 1.52 16 AMX86-D6 25 N.B. 9.82 1.43 24 AMX86-E6 51.3 N.B. 9.02 1.13 22 AMX86-F6 69.1 N.B. 10.17 1.36 18 AMX86-A7 57.7 667.9 11.58 3.99 1.59 14 AMX86-B7 111 934.1 8.42 7.81 1.46 20 AMX86-C7 140.3 N.B. 4.65 0.77 19 AMX86-E7 210.2 267.5 1.27 6.79 1.23 21 AMX86-F7 147 106.4 0.72 13.07 2.49 25 AMX86-H7 89.8 N.B. 10.85 1.26 26 AMX86-C8 107.1 N.B. 5.28 1.17 23 AMX86-D8 294.2 N.B. 6.87 1.08 17 AMX86-G8 133.7 2493.1 18.65 7.26 2.05 1-pt Round 8 X-IL-23 Screen Data IL-23 KD IL SEQ ID KD IL-12 KD 1 2 /KD IL- +/-IL-23 +/-IL-12 NO Clone Name (nM) (nM) 23 75 nM 75 nM 41 AMX86-A9 190.5 N.B. 3.55 0.68 35 AMX86-B9 23.7 847.6 35.76 12.88 1.96 32 AMX86-C9 97.9 672.8 6.87 6.07 1.86 33 AMX86-G9 109.4 N.B. 10.03 1.04 73 WO 2007/035922 PCT/US2006/037276 39 AMX86-H9 104.6 331.5 3.17 10.35 3.66 34 AMX86-A1O 460.9 289.4 0.63 6.64 1.40 28 AMX86-B1O 77.8 1038.3 13.35 4.73 2.12 42 AMX86-E1O 218.1 904.6 4.15 2.44 1.37 36 AMX86-G1O 73.7 356.1 4.83 9.88 2.41 37 AMX86-A11 157.2 182.4 1.16 7.05 3.23 29 AMX86-B11 179.9 5950 33.07 9.23 1.69 30 AMX86-DI1 198.9 113.9 0.57 10.26 2.59 38 AMX86-Fl1 255.64 540.6 2.11 7.33 2.87 40 AMX86-H11 366.9 214.9 0.59 7.56 3.02 31 AMX86-F12 423.7 2910.3 6.87 11.88 2.51 PN-IL-23 Clones 1-pt Screen Data +/-.

IL

PN-IL- IL-12 12 SEQ 23 IL-23 KD +/-IL-23 +/-IL-23 200 ID NO Clone Name Round KD(nM) (nM) 200 nM 100 nM nM 43 AMX 84-A10 RIO 22.3 N.B. 39.6 2.9 44 AMX 84-B10 RIO 21.8 N.B. 22.7 1.3 45 AMX 84-Al1 RIO 17.8 N.B. 32.7 1.8 46 AMX 84-F11 R10 16.6 N.B. 22.5 0.8 47 AMX 84-E12 R10 27.8 N.B. 15.8 0.8 48 AMX 84-C1O RIO 94.3 N.B. 17.7 2.2 49 AMX 84-C11 RIO 15.5 286.1 23.4 2.7 50 AMX 84-G11 RIO 290.7 N.B. 22.3 1.7 ARX33-platel 51 H01 R12 77.8 N.B. 20.3 1.7 52 AMX91-F11 R10 201.7 N.B. 11.4 2.2 53 AMX 91-G1 RIO 82.3 N.B. 52.2 1.7 54 AMX 91-E3 RIO 205.3 N.B. 34.4 2.9 55 AMX 91-H3 R10 265.7 N.B. 18.5 2.3 56 AMX 91-B5 R10 148.5 N.B. 11.2 0.9 57 AMX 91-A6 RIO 60.3 N.B. 6.3 1.1 58 AMX 91-G7 R12 63.6 N.B. 38.1 1.9 59 AMX 91-H7 R12 71.0 N.B. 44.7 1.4 74 WO 2007/035922 PCT/US2006/037276 60 AMX91-B8 R12 17.6 409.1 34.0 7.9 61 AMX 91-H8 R12 16.6 243.2 25.2 4.1 62 AMX 91-G9 R12 33.0 N.B. 31.7 1.1 63 AMX 91-D9 R12 44.6 N.B. 25.1 64 AMX91-G11 R12 104.4 N.B. 12.5 1.7 65 AMX 91-C12 R12 30.7 N.B. 22.9 1.9 66 AMX 91-H12 R12 60.8 N.B. 48.6 1.2 N.B. = no significant binding observed [00248] The nucleic acid sequences of the rRfY aptamers characterized in Table 5 are given below. The unique sequence of each aptamer below begins at nucleotide 25, immediately following the sequence GGGAAAAGCGAAUCAUACACAAGA (SEQ ID NO 11) and runs until it meets the 3'fixed nucleic acid sequence GCUCCGCCAGAGACCAACCGAGAA (SEQ ID NO 12). [002491 Unless noted otherwise, individual sequences listed below are represented in the 5' to 3' orientation and represent the sequences that bind to IL-23 and/or IL- 12 selected under rRfY SELEX m conditions wherein the purines (A and G) are 2'-OH and the pyrimidines (U and C) are 2'-fluoro. Each of the sequences listed in Table 5 may be derivatized with polyalkylene glycol ("PAG") moieties and may or may not contain capping (e.g., a 3'-inverted dT). [00250] Table 5. rRfY Clone sequences from h-IL-23 Selection (Round 8), X-IL-23 Selection (round 8), PN-IL-23 Selection (Roundl0/12). h-IL-23 Selection (Round 8) SEQ ID NO 13 (AMX(86)-D5) GGGAAAGCGAAUCAUACACAAGAGGUAUGUGGUUUUGCGGAGCAACUCGUGUCAGCGGUCAGCUCCGCCAGAGAC SEQ ID NO 14 (AMX(86)-B7) GCAACGAAUCAUACACAAGAAUGAAUUCCGUCCACGGGCGCCCGAUGAUGUCAGUUUUCGGCUCCGCCAGAGAC SEQ ID NO 15 (AMX(86)-B5) GGGAAAAGCGAAUCAUACACAAGAUUAGUGCGUGUGUUGAAAGGGCUCAUAAUGUCAGUAUCGAGCUCCGCCAGAGAC SEQ ID NO 16 (AMX(86)-D6) GGGAAAAGCGAAUCAUACACAAGAUUAGGCGUCGUGACAAIAACUGGUCCACGAGCAUGUCAGUGCUICCGCCAGAGAC 75 WO 2007/035922 PCT/US2006/037276 SEQ ID NO 17 (AMX(86)-G8) GGGAAAAGCGAAUCAUACACAAGAUGGAAGGCGAtUCGUAGCAGUAACCCAAUGAUUGGGACCUAGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 18 (AMX(86)-A7) GGGAAAAGCGAAUCAUACACAAGAUCUCUUUGGCCGACGCAACAAUGCUCUUUUCCGACCUUGCGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 19 (AMX(86)-E7) GGGAAAAGCGAAUCCUACCCAAGAUGUUGUUGGCGUUiGAUCGUAUGAUUNAUGGAGNGUGUCNGUGCUCCGCCAGAG ACCAACCGAGAA SEQ ID NO 20 (AMX(86)-C7) GGGAAAGCGAAUCAUACACAAGAUGCGCUAUGUUUGGCUGGGAAUUGUAGCAUJUGCUCAAGUGGCUCCGCCAGAGAC CAACCGAGiAA SEQ ID NO 21 (AMX(86)-F7) GGAAAAGCGAAUCAUACACAAGAUGUUGAACCUCUUJGUGCGUCCCGAUGUIUUNGCAAUGUGGCAGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 22 (AMX(86)-F6) GGGAAAAGCGAAUCAUACACAAGAAUGUAUACAAUGCCCUAUCGUCAGUUAGGCAUGUGUGGAUGCUCCGCCAGAGAC SEQ ID NO 23 (AMX(86)-D8) GGGAAAAGCGAAUCAUACACAAGACAGA.GGCAAUGAGAGCCUGGCGAUGUCAGUICGCAUCUUGCUGCUCCGCCAGAGA CCAACCGAGAA SEQ ID NO 24 (AMX(86)-E6) GGGAAAAGCGAAUCAUACACAAGAUCGCAAAAGGAGUUGUCUCUGCUCUCGGAGUGUGUCAGUGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 25 (AMX(86)-H7) GGGAAAAGCGAAUCAUACACAAGAGAUGACUJACACGCCAGUGUGCGCUUUUUGCGGAGUUAGCGGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 26 (AMX(86)-C8) GGGAAAAGCGAAUCAUACACAAGAGUCGUGAUGAUUUGGGUUAUGUCAGUUCCCIGUAUGGUUUCGCUCCGCCAGAGA CCAACCGAGAA SEQ ID NO 27 (AMX(86)-C5) GGAAAAGCGAAUCAUACACAAGAGUUUUAUGUGGGUCCCGAUGAUUAACUUIUAUUGGCGCAUUGCUCCGCCAGAGAC X-IL-23 Selection (Round 8) SEQ ID NO 28 (AMX(86)-B 10) GGGAAAAGCGAAUCAUACACAAGAGAACGAGUAUAUUUGCGCUGGCGGAGAAGUCUCUCGAAGGGAGCUCCGCCAGAG ACCAACCGAGAA SEQ ID NO 29 (AMX(86)-B11) GGGAAAAGCGAAUCAUACACAAGAGUAUCAUUCGGCUGGUGGGAGAAAUCUCUGUIAGAUAUAGAGCUCCGCCAGAGAC 76 WO 2007/035922 PCT/US2006/037276 SEQ ID NO 30 (AMX(86)-D1 1) GGGAAAAGCGAAUCAUACACAAGAUAGCGUCIAUGAUGGCGGAGAAGCAAGUGUAGCAUAACAGGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 31 (AMX(86)-F12) GGGAAAAGCGAAUCAUACACAAGAGUGUUGAAUGAGCGCUGGUGGACAGAUCUUUGGUUACAGAGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 32 (AMX(86)-C9) GGGAAAAGCGAAUCAUACACAAGACUCAUGGAUAUGGCCUAGCAGCCGUGGAAGCGGUCAIUCUGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 33 (AMX(86)-G9) GGGAAAAGCGAAUCAUACACAAGAUCCCAGCGGUACGUGAGUCUGUUAAAGGCCACCUIAAUGUCGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 34 (AMX(86)-A10) GGGAAAAGCGAAUCAUACACAAGAGUAAUGUGGGUCCCGAUGAUUCGCUGUGCGGCGUUUGUAGCUCCGCCAGAGACC AACCGAGAA SEQ ID NO 35 (AMX(86)-B9) GGGAAAAGCGAAUCAUACACAAGAGGUUGAGUACGACGGAGUCNUGGCUAACACGGAAACUAGAGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 36 (AMX(86)-G10) GGGAAAAGCGAAUCAUACACAAGAGUCAUGGCUUACAAUUGAAACAAGAGCUCGCGUGACACAUGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 37 (AMX(86)-A1 1) GGGAAAAGCGAAUCAUACACAAGAACGGCUAGGCAUCAAUGGCCAGCAAAAAUAGUCGUGUAAUGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 38 (AMX(86)-F1 1) GGGAAAAGCGAAUCAUACACAAGACCAUCGGACGAGGCGGGUCACCUUUUACGCUUUCGAGCUGGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 39 (AMX(86)-H9) GGGAAAAGCGAAUCAUACACAAGAUGGUUCCCACGUGAAAGUGGCUAGCGAGUACCCCACUUAUGCUCCGCCAGAGAC CAACCAAGGG SEQ ID NO 40 (AMX(86)-H11) GGGAAAAGCGAAUCAUACACAAGAGCGCUUUAGCGGGUAUAGCACUUUJCAUCUAAUGAANCCGLAGCUCCGCCAGAG ACCAACCGAGAA SEQ ID NO 41 (AMX(86)-A9) GGGAAAAGCGAAUCAUACACAAGAUCUACGAUUGUUCAGGUUUUUUGUACUCAACUAAAGGCGAGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 42 (AMX(86)-E10) GGGAAAAGCGAAUCAUACACAAGAUUGUCUCGGALIUGGUCACUCCCAUUUUUGUUCGCUUAACGGCUCCGCCAGAGAC CAACCGAGAA 77 WO 2007/035922 PCT/US2006/037276 PN-IL-23 Selection (Round 10 and 12) SEQ ID NO 43 (AMX(84)-A1O) GGGAAAGCGAAUCAUACACAAGAAGUUUUUUGUGCUCUGAGUACUCAGCGUCCGUAAGGGAUAUGCUCCGCCAGAGA CCAACCGAGAA SEQ ID NO 44 (AMX(84)-B 10) GGGAAAAGCGAAUCAUACACAAGAAGUGCUUCAUGCGGCAAACUGCAUGACGUCGAAUAGAUAUGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 45 (AMX(84)-A11) GGGAAAAGCGAAUCAUACACAAGAGAGGUAUGUGGUUUUGCGGAGCAACUCGUGUCAGCGGUCAGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 46 (AMX(84)-F11) GGGAAAAGCGAAUCAUACACAAGAUGUGCUUGAGUUAAAUCUCAUCGUCCCCGUUUGGGGAUAUGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 47 (AMX(84)-E12) GGGAAAAGCGAAUCAUACACAAGAAGUULUUGUGCUCUGAGUACUCAGCGUCCGUAAGGGAUAUGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 48 (AMX(84)-C 10) GGGAAAAGCGAAUCAUACACAAGAGAUGUAUUCAGGCGGUCCGCAUUGAUGUCAGUUAUGCGUAGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 49 (AMX(84)-C11) GGGAAAAGCGAAUCAUACACAAGAAUGGUCGGAAUCUCUGGCGCCACGCUGAGUAUAGACGGAAGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 50 (AMX(84)-G11) GGGAAAAGCGAAUCAUACACAAGAGUGCUUCGUAUGUUGAAUACGACGUUCGCAGGACGAAUAUGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 51 (ARX33-platel-HO1) AGGGAAAAGGAAUCAUACACAAGAUGUAUCAUCCGGUCGUACAAAAGCGCCACGGAACCAUUCGCUCCGCCAGANACC AACCGAGAA SEQ ID NO 52 (AMX(91)-F11) GGGAAAAGCGAAUCAUACACAAGACGCGUCAGGUCCACGCUGAAAUUUAUUUUCGGCAGUGUAAGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 53 (AMX(91)-G1) GGGAAAAGCGAAUCAUACACAAGAUAUGUGCCUGGGAUGGACGACAUCCCCUGUCUAAGGAUAUGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 54 (AMX(91)-E3) GGGAAAAGCGAAUCAUACACAAGAUIACUCCGULAGUGUCAGUUGACGGAGGGAGCGUACUAUUGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 55 (AMX(91)-H3) GGGAAAAGCGAAUCAUACACAAGACAUUGUGCUUUAUCACGUGGGUGAUAACGACGAAAGUUAUGCUCCGCCAGAGAC CAACCGAGAA 78 WO 2007/035922 PCT/US2006/037276 SEQ ID NO 56 (AMX(91)-B5) GGGAAAAGCGAAUCAUACACAAGACAGUGUAUJGAGGAAGAUJUACUUCCAUUCCUGAGCGGUULJUCGCICCGCCAGAGA CCAACCGAGAA SEQ ID NO 57 (AMX(91)-A6) GGGAAAAGCGAAUCAUACACAAGAUUGGCAAUGUGACCUUCAACCCUUUUCCCGAUGAACAGUGGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 58 (AMX(91)-G7) GGGAAAAGCGAAUCAUACACAAGACAUGACUGCAUGCLJUCGGGAGUAUCUCGGUCCCGACGUUCGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 59 (AMX(91)-H7) GGGAAAAGCGAAUCAUACACAAGACUUAUCGCCUCAAGGGGGGUAAUAAACCCAGCGUGUGCAUGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 60 (AMX(91)-B8) GGGAAAAGCGAAUCAUACACAAGAAUCCUGGCUUCGCAUAGUGUAUGGGUAGUACGACAGCGCGIGCUCCGCCAGAGA CCAACCGAGAA SEQ ID NO 61 (AMX(91)-H8) GGGAAAAGCGAAUCAUACACAAGAACGCAUAGUCGOAUUUACCGAUCAUJUCUGUGCCUUCGUGACGCUCCGCCAGAGA CCAACCGAGAA SEQ ID NO 62 (AMX(91)-G9) GGGAAAAGCGAAUCAUACACAAGAAUUGUGCUUACAACUUUCGUUGUACCGACGUGUICAGUUAUGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 63 (AMX(91)-D9) GGGAAAAGCGAAUCAUACACAAGAGUGUAUUACCCCCAACCCAGGGGGACCAUJUCGCGUAACAAGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 64 (AMX(91)-Gl 1) GGGAAAAGCGAAUCAUACACAAGACUJAACAGUGCGGGGCGCAGUGUAUAGAUCCGCAAUGUGUGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 65 (AMX(91)-C12) GOGAAAAGCGAAUCAUACACAAGACGAUAGUALIGACCUUUUGAAAGGCUUCCCGAGCGGUGUUCGCUCCGCCAGAGAC CAACCGAGAA SEQ ID NO 66 (AMX(91)-H12) GGGAAAAGCGAAUCAUACACAAGACGUGLGCUUUAUGUAAACCAUAACGUICCAUAAGGAAUAUGCUCCGCCAGAGAC CAACCGAGAA [002511 Those sequences having binding activity to the IL-23 target proteins as determined by the dot blot binding assay described above, and that were functional in cell based assays (described below in Example 3), were minimized (described below in Example 2). 79 WO 2007/035922 PCT/US2006/037276 EXAMPLE 1B: IL-23 Selections against human IL-23 with ribo/2'O-Me nucleotide containing pools [00252] Two selections were performed to identify aptamers containing ribo/2'O-Methyl nucleotides. One selection used 2'O-Methyl A, C, and U and 2'OH G (rGmli), and the other selection used 2'-OMe C, U and 2'-OH G, A (rRmY). Both selections were direct selections against h-IL-23 which had been immobilized on a hydrophobic plate. No steps were taken to bias selection of aptamers specific for the p19 or p40 subdomains. Both selections yielded pools significantly enriched for h-IL-23 binding versus naYve, unselected pool. Individual clone sequences are reported herein, and h-IL-23 binding data is provided for selected individual clones. [00253] Pool Preparation. A DNA template with the sequence 5'

GGGAGAGGAGAGAACGTTCTACN

3 0CGCTGTCGATCGATCGATCGATG-3' (ARC256) (SEQ ID NO 3) was synthesized using an ABI EXPEDITETM DNA synthesizer, and deprotected by standard methods. The series of N's in the DNA template (SEQ ID NO 3) can be any combination of nucleotides and gives rise to the unique sequence region of the resulting aptamers. [00254] The template was amplified with the 5' primer 5' TAATACGACTCACTATAGGGAGAGGAGAGAACGTTCTAC-3' (SEQ ID NO 67) and 3' primer 5'-CATCGATCGATCGATCGACAGC-3' (SEQ ID NO 68) and then used as a template for in vitro transcription with Y639F single mutant T7 RNA polymerase. Transcriptions were done at 370 C overnight using 200 mM Hepes, 40 mM DTT, 2 mM spermidine, .01% Triton X-100, 10% PEG-8000, 5 mM MgCl 2 , 1.5 mM MnCl 2 , 500 IM NTPs, 500 iM GMP, 0.01 units/pL inorganic pyrophosphatase, and 2 ig/mL Y639F single mutant T7 polymerase. Two different compositions were transcribed, rGmH, and rRmY. [002551 Selection. Each round of selection was initiated by immobilizing 20 pmoles of h-IL-23 to the surface of Nunc Maxisorp hydrophobic plates for 2 hours at room temperature in 100 ptL of IX Dulbecco's PBS (DPBS (+Ca 2 +, Mg 2 +)). The supernatant was then removed and the wells were washed 4 times with 120 pL wash buffer (lX DPBS, 0.2% BSA, and 0.05% Tween-20). Pool RNA was heated to 901C for 3 minutes and cooled to room temperature for 10 minutes to refold. In Round 1, a positive selection step was conducted. Briefly, 1 x 1014molecules (0.2 nmoles) of pool RNA were incubated in 100 iL binding buffer (1X DPBS and 0.05% Tween-20) in the wells with immobilized protein 80 WO 2007/035922 PCT/US2006/037276 target for 1 hour. The supernatant was then removed and the wells were washed 4 times with 120 pL wash buffer. In subsequent rounds a negative selection step was included. The pool RNA was also incubated for 30 minutes at room temperature in empty wells to remove any plastic binding sequences from the pool before the positive selection step. The number of washes was increased after Round 4 to increase stringency. In all cases, the pool RNA bound to immobilized h-IL-23 was reverse transcribed directly in the selection plate by the addition of RT mix (3' primer, (SEQ ID NO 68), and Thermoscript" RT, (Invitrogen, Carlsbad, CA) followed by incubation at 65'C for 1 hour. [00256] The resulting cDNA was used as a template for PCR using Taq polymerase (New England Biolabs, Beverly, MA). "Hot start" PCR conditions coupled with a 60'C annealing temperature were used to minimize primer-dimer formation. Amplified pool template DNA was desalted with a Centrisep column (Princeton Separations, Adelphia, NJ) according to the manufacturer's recommended conditions, and used to transcribe the pool RNA for the next round of selection. The transcribed pool was gel purified on a 10 % polyacrylamide gel every round. Table 6 shows the RNA concentration used per round of selection. [00257] Table 6. RNA pool concentrations per round of selection. Round rRmY rGmH poless pool used) (pmoles pool used) 1 200 200 2 110 40 3 65 100 4 50 170' 5 80 100 6 100 110 7 50 70 8 120 60 9 120 80 10 130 11 110 81 WO 2007/035922 PCT/US2006/037276 [002581 The selection progress was monitored using the dot blot sandwich filter binding assay as described in Example IA. The 5'- 32 P-labeled pool RNA was refolded at 90'C for 3 minutes and cooled to room temperature for 10 minutes. Next, pool RNA (trace concentration) was incubated with h-IL-23 DPBS plus 0.1 mg/mL tRNA for 30 minutes at room temperature and then applied to a nitrocellulose and nylon filter sandwich in a dot blot apparatus (Schleicher and Schuell). The percentage of pool RNA bound to the nitrocellulose was calculated and monitored approximately every 3 rounds with a single point screen (+/- 250 nM h-IL-23). Pool KD measurements were measured using a titration of h-IL-23 protein (R&D, Minneapolis, MN) and the dot blot apparatus as described above. [002591 The rRmY h-IL-23 selection was enriched for h-IL-23 binding vs. the naYve pool after 4 rounds of selection (data not shown). The selection stringency was increased and the selection was continued for 8 more rounds. At Round 9 the pool KD was approximately 500 nM or higher. The rGmH selection was enriched over the naYve pool binding at Round 10. The pool KD was also approximately 500 nM or higher. Figure 7 is a binding curve of rRmY and rGmH pool selection binding to h-IL-23. The pools were cloned using TOPO TA cloning kit (Invitrogen, Carlsbad, CA) and individual sequences were generated and tested for binding. A single point binding screen was initially perfonned on all crude rRmY clone transcriptions using a 1:200 dilution, +/- 200 nM IL-23, plus 0.1 mg/mL competitor tRNA. A 10 point screen was then performed on 24 of the rRmY clones which showed the best binding in the single point screen. The 10 point screen was performed using zero to 480 nM IL-23 in 3 fold serial dilutions. Binding curves were generated (KaleidaGraph v. 3.51, Synergy Software) and KDs were estimated by fitting the data to the equation: fraction RNA bound = amplitude*[h-IL-23]/KD + [h-IL-23]). Table 7 below shows the sequence data for the rRmY selected aptamers that displayed binding affinity for h-IL-23. There was one group of 6 duplicate sequences and 4 pairs of 2 duplicate sequences out of the rRnY clones generated. Table 8 shows the binding characteristics of the rRmY clones thus tested. Clones were also tested from 48 crude rGmH clone transcriptions at a 1:200 dilution and 0.1 mg/mL tRNA was used as competitor. The average binding over background was only about 14%, whereas the average of the rRiY clones in the same assay was about 30%, with 10 clones higher than 40%. The sequences and binding characterization of the rGmH clones tested are not shown. [00260] The nucleic acid sequences of the rIRmY aptamers characterized in Table 7 are given below. The unique sequence of each aptamer in Table 7 begins at nucleotide 23, 82 WO 2007/035922 PCT/US2006/037276 immediately following the sequence GGGAGAGGAGAGAACGUUCUAC (SEQ ID NO 69), and runs until it meets the 3'fixed nucleic acid sequence GCUGUCGAUCGAUCGAUCGAUG (SEQ ID NO 70). [00261] Unless noted otherwise, individual sequences listed below are represented in the 5' to 3' orientation and represent the sequences of the aptamers that bind to IL-23 and/or IL 12 selected under rRmY SELEXM conditions wherein the purines (A and G) are 2'-OH and the pyrimidines (U and C) are 2'-OMe. Each of the sequences listed in Table 7 may be derivatized with polyalkylene glycol ("PAG") moieties and may or may not contain capping (e.g., a 3'-inverted dT). [0002] Table 7 - rRnY (Round 10) Sequences SEQ ID NO 71 GGGAGAGGAGAGAACGUUCUACAAAUGAGAGCAGGCCGAAGAGGAGUCGCUCGCUGUCGAUCGAUCGAUCGAUG SEQ ID NO 72 GGGAGAGGAGAGAACGUUCUACAAAUGAGAGCAGGCCGAAAAGGAGUCGCUCGCUGJCGAUCGAUCGAUCGAG SEQ ID NO 73 GGGAGAGGAGAGAACGUUCUACAAAUGAGAGCAGGCCGAAAAGGAGUCGCUCGCUGUCGAUCGAUCGAUCGAUG SEQ ID NO 74 GGGAGAGGAGAGAACGUUCUACGGUAAAGCAGGCUGACIGAAAGGUUGAAGUCGCUGUCGALCGAUCGAUCGAUG SEQ ID NO 75 GGGAGAGGAGAGAACGUUCUACAGGUUAAGAGCAGGCUCAGGAAUGGAAGUCGCUGUCGAUCGAUCGAUCGAUG SEQ ID NO 76 GGGAGAGGAGAGAACGUUCUACAACAAAGCAGGCUCAUAGUAAUAUGGAAGUICGCUGUCGAUICGAUCGAUCGAUG SEQ ID NO 77 GGGAGAGGAGAGAACGUUCUACAACAAAGCAGGCUCAUAGUAAUAUGGAAGUCGCUGUCGAUCGAUCGAUCGAUG SEQ ID NO 78 GGGAGAGGAGAGAACGUUCUACAAAAGAGAGCAGGCCGAAAAGGAGUCGCICGCUGJCGAUCGAUCGAUCGAUG SEQ ID NO 79 GGGAGAGGAGAGAACGUUCUACAAAAGGCAGGCUCAGGGGAUCACJGGAAGUCGCUGUCGAUCGAUCGAUCGAUG SEQ ID NO 80 GGGAGAGGAGAGAACGUUCUACAAGAUAUAAUUAAGGAUAAGUGCAAAGGAGACGCUGICGAUCGAUCGAUCGAUG SEQ ID NO 81 GGOAGAGGAGAGAACGUUCUACGAAUGAGAGCAGGCCGAAAAGGAGUCGCUCGCUGUCGAUCGAUCGAUCGAUG SEQ ID NO 82 GGGAGAGGAGAGAACGUUCUACGAGAGGCAAGAGAGAGUCGCAUAAAAAAGACGCUGUCGAUCGAUCGAUCGAUG 83 WO 2007/035922 PCT/US2006/037276 SEQ ID NO 83 GGGAGAGGAGAGAACGUUCUACGCAGGCUGUCGUAGACAAACGAUGAAGUCGCGCUGUCGAUCGAUCGAUCGAUG SEQ ID NO 84 GGGAGAGGAGAGAACGUUCUACGGAAAGAUAUGAAGAAGGAUJGAGACGCUGUCGAUCGAUCGAUCGAUG SEQ 11) NO 85 GGGAGAGGAGAGAACGUUCUACGGAAGGNAACANAGCACUGUUJGUGCAGGCGCUGUCGAUCNAUCNAUCNAUG SEQ ID NO 86 GGGAGAGGAGAGAACGUUCUACUAAUGCAGGCUCAGUUACUACUGGAAGUCGCUGUCGAUCGAUfCGAUCGAUG SEQ ID NO 87 AGGAGAGGAGAGAACGUUCUACUAGAGCAGGCUCGAAUACAAUUCGGAGUCGCUGUCGAUCGAUCGAUCGAUG SEQ ID NO 88 GGGAGAGGAGAGAACGUUCUACAUAAGCAGGCUCCGAUAGUAUUCGGGAAGUCGCUGUCGAUCGAUCGAUCGAU [002621 Table 8 - rRrnY IL-23 Clone Binding Data. SQ IL-23 KD ID No. (nM) 72 211.4 83 8.2 86 219.3 80 3786.3 75 479.4 74 257.0 81 303.2 77 258.9 73 101.4 88 101.2 84 602.5 78 123.7 76 77.2 87 122.3 71 124.0 85 239.9 84 WO 2007/035922 PCT/US2006/037276 82 198.6 79 806.7 **Assays performed in IX DPBS (+Ca 2 +, Mg 2 +), 30 min RT incubation **R&D IL-23 (carrier free protein) EXAMPLE 1C: Selections against human IL-23 with deoxy/2'O-Methyl nucleotide containing pools [00263] An alternative selection was performed to obtain stabilized aptamers specific for IL-23 using deoxy purines (A and G) and 2'-O-Me pyrimidines (C and U) using the h-IL-23 strategy. [002641 Pool Preparation. A DNA template with the sequence 5'

GGGAGAGGAGAGAACGTTCTACN

3 oCGCTGTCGATCGATCGATCGATG-3' (ARC256, SEQ ID NO 3) was synthesized using an ABI EXPEDITETM DNA synthesizer, and deprotected by standard methods. The series of N's in the DNA template (SEQ ID NO 3) can be any combination of nucleotides and gives rise to the unique sequence region of the resulting aptamers. The templates were amplified with the 5' primer 5' TAATACGACTCACTATAGGGAGAGGAGAGAACGTTCTAC-3' (SEQ ID NO 67) and 3' primer 5'-CATCGATCGATCGATCGACAGC-3' (SEQ ID NO 89) and then used as a template for in vitro transcription with Y639F single mutant T7 RNA polymerase. Transcriptions were done at 37* C overnight using 200 mM Hepes, 40 mM DTT, 2 mM spermidine, 0.01% Triton X-100, 10% PEG-8000, 9.6 mM MgCl 2 , 2.9 mM MnCl 2 , 2 mM NTPs, 2 mM GMP, 2 mM spermine, 0.01 units/pL inorganic pyrophosphatase, and 2 pig/mL Y639F single mutant T7 polymerase. [00265] Selection: Each round of selection was initiated by immobilizing 20 pmoles of h IL-23 to the surface of Nunc Maxisorp hydrophobic plates for 1 hour at room temperature in 100 LL of 1X PBS. The supernatant was then removed and the wells were washed 5 times with 120 piL wash buffer (1X PBS, 0.1 mg/mL tRNA and 0.1 mg/mL salmon sperm DNA ("ssDNA")). In Round 1, a positive selection step was conducted: 100 poles of pool RNA (6 x 101 3 unique molecules) were incubated in 100 pL binding buffer (lX PBS, 0.1 mg/mL tRNA and 0.1 mg/mL ssDNA) in the wells with immobilized protein target for 1 hour. The supernatant was then removed and the wells were washed 5 times with 120 piL wash buffer. In subsequent rounds a negative selection step was included. The pool RNA was also 85 WO 2007/035922 PCT/US2006/037276 incubated for 1 hour at room temperature in empty wells to remove any plastic binding sequences from the pool before the positive selection step. Starting at Round 3, a second negative selection step was introduced. The target-immobilized wells were blocked for 1 hour at room temperature in 100 pL blocking buffer (IX PBS, 0.1 mg/mL tRNA, 0.1 mg/mL ssDNA and 0.1 mg/mL BSA) before the positive selection step. In all cases, the pool RNA bound to immobilized h-IL-23 was reverse transcribed directly in the selection plate after by the addition of RT mix (3' primer, (SEQ ID NO 89)), and Thermoscript" RT (Invitrogen, Carlsbad, CA), followed by incubation at 65 0 C for I hour. The resulting cDNA was used as a template for PCR (Taq polymerase, New England Biolabs, Beverly, MA). "Hot start" PCR conditions coupled with a 68'C annealing temperature were used to minimize primer-dimer formation. Amplified pool template DNA was desalted with a Micro Bio-Spin column (Bio-Rad, Hercules, CA) according to the manufacturer's recommended conditions and used to program transcription of the pool RNA for the next round of selection. The transcribed pool was gel purified on a 10 % polyacrylamide gel every round. [00266] Protein Binding Analysis. The selection progress was monitored using the sandwich filter binding assay previously described in Example IA. The 5'- 32 P-labeled pool RNA (trace concentration) was incubated with h-IL-23, IX PBS plus 0.1 mg/mL tRNA, 0.1 mg/mL ssDNA and 0.1 mg/mL BSA for 30 minutes at room temperature and then applied to a nitrocellulose and nylon filter sandwich in a dot blot apparatus (Schleicher and Schuell, Keene, NH). The percentage of pool RNA bound to the nitrocellulose was calculated after Rounds 6, 7 and 8 with a seven point screen with h-IL-23 (0.25 nM, 0.5 nM, 1 nM, 4 nM, 16 nM, 64 nM and 128 nM). Pool KD measurements were calculated as previously described. [002671 The dRmY IL-23 selection was enriched for h-IL-23 binding vs. the naYve pool after 6 rounds of selection. At Round 8 the pool KD was approximately 54 nM or higher. The Round 6, 7 and 8 pools were cloned using a TOPO TA cloning kit (Invitrogen, Carlsbad, CA) and individual sequences were generated. Table 9 lists the sequences of the dRmY clones generated from Round 6, 7 and 8 pools. Protein binding analysis was perfonned for each clone. Binding assays were performed in lX PBS +0.1 mg/mL tRNA, 0.1 mg/mL salmon sperm DNA, 0.1 mg/mL BSA, for a 30 minute incubation at room temperature. Table 10 includes the binding characterization for these individual sequences. 86 WO 2007/035922 PCT/US2006/037276 [00268] The nucleic acid sequences of the dRmY aptamers characterized in Table 9 are given below. The unique sequence of each aptamer below begins at nucleotide 23, immediately following the sequence GGGAGAGGAGAGAACGUUCUAC (SEQ ID NO 69), and runs until it meets the 3'fixed nucleic acid sequence GCUGUCGAUCGAUCGAUCGAUG (SEQ ID NO 90). [002691 Unless noted otherwise, individual sequences listed below are represented in the 5' to 3' orientation and represent the sequences of the aptamers that bind to IL-23 and/or IL 12 selected under dRmY SELEX " conditions wherein the purines (A and G) are deoxy and the pyrimidines (U and C) are 2'-OMe. Each of the sequences listed in Table 9 may be derivatized with polyalkylene glycol ("PAG") moieties and may or may not contain capping (e.g., a 3'-inverted dT). [00270] Table 9. dRmY IL-23 clone sequences SEQ ID NO 91 (ARC 489) GGGAGAGGAGAGAACGUUCUACAGCGCCGGUGGGCGGGCAUUGGGUGGAUGCGCUGUCGAUCGAUCGAUCGAUG SEQ ID NO 92 (ARC 490) GGGAGAGGAGAGAACGUUCUACAGCCUUUUGGGUAAGGGGAGGGGUGCCGGUCGCUGUCGAUCGAUCGAUCGAUG SEQ ID NO 93 GGGAGAGGAGAGAACGUUCUACGUAACGGGGUGGGAGGGGCGAACAACUUGACGCUGUCGAUCGAUCGAUCGAUG SEQ ID NO 94 (ARC 491) GGGAGAGGAGAGAACGUUCUACAGCGCCGGUGGGUGGGCAUAGGGUGGAUGCGCUGUCGAUCGAUCGAUCGAUG SEQ ID NO 95 GGGAGAGGAGAGAACGUUCUACGGGCUACGGGGAUGGAGGGUGGGLCCCAGACGCUGUCGAUCGAUCGAUCGAUG SEQ ID NO 96 GGGAGAGGAGAGAACGUUCUACACGGGGUGGGAGGGGCGAGUCGCAUGGAUJGCGCLIGUCGAUCGAUCGAUCGAUG SEQ ID NO 97 (ARC492) GGGAGAGGAGAGAACGUUCUACUCAAUGACCGCGCGAGGCUCUGGGAGAG GGCGCUGUCGAUCGAUCGAUCGAUG [00271] Table 10 - dRmY IL-23 aptamer binding data SEQ IL-12 KD ID No. IL-23 KD (nM) (nM) 91 4.0 17.2 92 26.0 37.1 87 WO 2007/035922 PCT/US2006/037276 93 186.2 Not tested 94 17.1 93.0 95 432.6 Not tested 96 209.7 Not tested 97 NB NB **Assays performed in 1X PBS + 0.1 mg/mL tRNA, 0.1mg/mL ssDNA, 0.1mg/mL BSA, 30 min RT incubation **R&D IL-23 (carrier free protein) N.B.= no binding detectable EXAMPLE ID: Additional Selections against human IL-23 with deoxy/2'O-Methyl nucleotide containing pools [00272] Introduction: Three selections strategies were used to identify aptamers to h-IL 23 using a pool containing deoxy/2'O-Methyl nucleotides. These selections used 2'O-Me C, and U and deoxy A and G. The first selection strategy (dRmY h-IL-23) was a direct selection against h-IL-23. In the second selection strategy (dRmY h-IL-23/IL-12neg), h-IL 12 was included in the negative selection step to drive enrichment of aptamers binding to p19, the subdomain unique to h-IL-23. In the third selection strategy (dRmY h-IL-23 -S), increased stringency was used in the positive selection by including long washes to drive the selection to select for higher affinity aptamers. All three selection strategies yielded aptamers to h-IL-23. Several aptamers are specific for h-IL-23, and several show cross reactivity between h- IL-23 and h-IL-12. [00273] dRmY Selection: Round 1 of the dRmY h-IL-23 selection began with 3x10 14 molecules of a 2'O-Me C, and U and deoxy A and G modified RNA pool with the sequence 5'-GGGAGAGGAGAGAACGUCUAC-N30 GGUCGAUCGAUCGAUCAUCGAUG -3' (ARC520) (SEQ ID NO 98), which was synthesized using an ABI EXPEDITETM DNA synthesizer, and deprotected by standard methods. The series of N's in the template (SEQ ID NO 98) can be any combination of nucleotides and gives rise to the unique sequence region of the resulting aptamers. [00274] Each round of selection was initiated by immobilizing 20 poles of h-IL-23 to the surface of Nunc Maxisorp hydrophobic plates for 1 hour at room temperature in 100 pL of 1X PBS. The supernatant was then removed and the wells were washed 5 times with 120 pL wash buffer (IX PBS, 0.1 mg/mL tRNA and 0.1 mg/mL salmon sperm DNA ("ssDNA")). In Round 1, 500 pmoles of pool RNA (3x10 14 molecules) were incubated in 88 WO 2007/035922 PCT/US2006/037276 100 pL binding buffer (IX PBS, 0.1 mg/mL tRNA and 0.1 mg/mL ssDNA) in the well with immobilized protein target for 1 hour. The supernatant was then removed and the well was washed 5 times with 120 pL wash buffer. In subsequent rounds a negative selection step was included in which pool RNA was also incubated for 1 hour at room temperature in an empty well to remove any plastic binding sequences from the pool before the positive selection step. [002751 Starting at Round 3, a second negative selection step was introduced. The pool was subjected to a 1 hour incubation in target-immobilized wells that were blocked for 1 hour at room temperature with 100 jiL blocking buffer (IX PBS, 0.1 mg/mL tRNA, 0.1 mg/mL ssDNA and 0.lmg/mL BSA) before the positive selection step (Table l lA). At Round 3, the dRmY h-IL-23 pool was split into the dRinY h-IL-23/IL- 1 2neg selection by subjecting the pool to an additional 1 hour negative incubation step at room temperature in a well that had been blocked for 1 hour at room temperature with 20 pmoles of h-IL- 12 and washed 5 times with 120 pL wash buffer, which occurred prior to the positive h-IL-23 positive incubation. The pool was split into additional h-IL-12 blocked wells in later rounds to increase the stringency (See Table 1 1B). [002761 An additional method to increase discrimination between h-IL-23 and h-IL- 12 binding was to add h-IL-12 to the positive selection along with the pool at a low concentration, in which the specific h-IL-23 binders would bind to the immobilized h-IL-23, and the h-IL- 12 binders would be washed away after the 1 hour incubation. The dRmY h IL-23-S selection was split from the dRmY h-IL-23 pool at Round 6 with the addition of "stringent washes" in the positive selection, in which after the 1 hour incubation with h-IL 23, the pool was removed, then 100 gL of IX PBS, 0.1 mg/imL tRNA, and 0.1 mg/mL ssDNA was added and incubated for 30 minutes (Table 11 C). This stringent wash procedure was removed and repeated, with the intentions of selecting for molecules with high affinities. [002771 In all cases, the pool RNA bound to immobilized h-IL-23 was reverse transcribed directly in the selection plate by the addition of RT mix (3' primer, 5' CATCGATGATCGATCGATCGAC-3' (SEQ ID NO 100)), and Thermoscriptm RT, (Invitrogen, Carlsbad, CA) followed by incubation at 65'C for I hour. The resulting cDNA was used as a template for PCR (20 mM Tris pH 8.4, 50 mM KCI, 2 mM MgCl 2 , 0.5 piM of 5' primer 5'-TAATACGACTCACTATAGGGAGAGGAGAGAACGTTCTAC-3' (SEQ 89 WO 2007/035922 PCT/US2006/037276 ID NO 99), 0.5 pM of 3' primer (SEQ ID NO 100), 0.5 mM each dNTP, 0.05 units/pL Taq polymerase (New England Biolabs, Beverly, MA)). PCR reactions were done under the following cycling conditions: a): 94*C for 30 seconds; b) 55'C for 30 seconds; c) 72*C for 30 seconds. The cycles were repeated until sufficient PCR product was generated. The minimum number of cycles required to generate sufficient PCR product is reported in Tables 11 A-1 1C as the "PCR Threshold". [00278] The PCR templates were purified using the QIAquick PCR purification kit (Qiagen, Valencia, CA) and used to program transcription of the pool RNA for the next round of selection. Templates were transcribed overnight at 37 0 C using 200 mM Hepes, 40 mM DTT, 2 mM spennidine, 0.01% Triton X-100, 10% PEG-8000, 9.6 mM MgC1 2 , 2.9 mM MnC1 2 , 2 mM NTPs, 2 mM GMP, 2 mM spermine, 0.01 units/RL inorganic pyrophosphatase, and 2 pg/mnL Y639F single mutant T7 polymerase. Transcription reactions were quenched with 50 mM EDTA and ethanol precipitated, then purified on a 1.5 mm denaturing polyacrylamide gel (8 M urea, 10% acrylamide; 19:1 acrylamide:bisacrylamide). Pool RNA was removed from the gel by passive elution at 37'C in 300 mM NaOAc, 20 mM EDTA, followed by ethanol precipitation. The selection conditions for each round are provided in the following tables. [002791 Table 11A: dRmY hIL-23 selection conditions IL-23 RNA

BSA

pool IL-23 blocked Round conc conc untreated well PCR # (pM) (p.M) well neg neg Threshold 1 5 0.2 none none 18 2 0.6 0.2 lhr none 17 3 0.75 0.2 lhr 1hr 17 4 1 0.2 1hr 1hr 17 5 0.75 0.2 1hr lhr 17 6 1 0.2 1hr 1hr 15 7 1 0.2. 1hr lhr 15 8 1 0.2 lhr 1hr 16 [00280] Table 11B: dRmY IL-23/IL-12neg selection conditions 90 WO 2007/035922 PCT/US2006/037276 IL-23/12neg RNA BSA- IL-12 IL-12 pool IL-23 blocked neg # IL- pos Round conC conC untreated well conc 12 cone PCR # (pM) (pM) well neg neg (JpM) wells (pM) Threshold 1 5 0.2 none none 0 0 0 18 2 0.6 0.2 1hr none 0 0 0 17 3 0.75 0.2 1hr 1hr 0.2 1 0 17 4 1 0.2 11h 1hr 0.2 1 0 17 5 0.75 0.2 lhr 1hr 0.2 2 0 17 6 1 0.2 lhr 1hr 0.2 2 0 15 7 1 0.2 lhr 1hr 0.2 3 0.02 15 8 1 0.2 1lhr 1hr 0.2 3 0.05 15 [00281] Table 11C: dRmY hIL-23-S selection conditions IL-23S RNA BSA- # pool IL-23 blocked 30min Round conc conc untreated well positive PCR # .(pM) (pM) well neg neg washes Threshold 1 5 0.2 none none 0 18 2 0.6 0.2 1hr none 0 17 3 0.75 0.2 1hr lhr 0 17 4 1 0.2 lhr Ihr 0 17 5 0.75 0.2 1hr 1hr 0 17 6 1 0.2 1hr 1hr 2 15 7 1 0.2 1hr 1hr 2 16 8 1 0.2 lhr 1hr 2 16 [002821 Protein Binding Analysis: Dot blot binding assays were performed throughout the selections to monitor the protein binding affinity of the pools as previously described in Example 1A. When a significant positive ratio of binding of RNA in the presence of h-IL 23 versus in the absence of h-IL-23 was seen, the pools were cloned using a TOPO TA cloning kit (Invitrogen, Carlsbad, CA) according to the manufacturer's instructions. Similar sequences were seen in all three selections from the pools having gone through six rounds, 91 WO 2007/035922 PCT/US2006/037276 and 45 unique clones amongst the three selections were chosen for screening. The 45 clones were synthesized on an ABI EXPEDITETM DNA synthesizer, then deprotected by standard methods. The 45 individual clones were gel purified on a 10% PAGE gel, and the RNA was passively eluted in 300 mM NaOAc and 20 mM EDTA, followed by ethanol precipitation. [00283] The clones were 5'end labeled with y- 32 P ATP, and were assayed for both IL-23 and IL-12 binding in a 3-point dot blot screen (0 nM, 20 nM, and 100 nM h-IL-23; 0 nM, 20 nM, and 100 nM h-IL-12) (data not shown). Clones showing significant binding in the 20 nM and 100 nM protein conditions for both IL-23 and IL- 12 were further assayed for KD determination using a protein titration from 0 nM to 480 nM (3 fold dilutions) in the dot blot assay previously described. KD values were determined by fitting an equation describing a 1:1 RNA:protein complex to the resulting data (fraction aptamer bound = amplitude*([IL-23]/( KD + [IL-23])) + background binding) (KaleidaGraph v. 3.51, Synergy Software). Results of protein binding characterization for the higher affinity clones are tabulated in Table 13, and corresponding clone sequences are listed in Table 12. [00284] The nucleic acid sequences of the dRnY aptamers characterized in Table 12 are given below. The unique sequence of each aptamer below begins at nucleotide 23, immediately following the sequence GGGAGAGGAGAGAACGUUCUAC (SEQ ID NO 10 1), and runs until it meets the 3'fixed nucleic acid sequence GUCGAUCGAUCGAUCAUCGAUG (SEQ ID NO 102). [002851 Unless noted otherwise, individual sequences listed below are represented in the 5' to 3' orientation and represent the sequences of the aptamers that bind to IL-23 and/or IL 12 selected under dRmY SELEX m conditions wherein the purines (A and G) are deoxy and the pyrimidines (C and U) are 2'-OMe. Each of the sequences listed in Table 12 may be derivatized with polyalkylene glycol ("PAG") moieties and may or may not contain capping (e.g., a 3'-inverted dT). [00286] Table 12: dRmY clone sequences SEQ ID NO 103 (ARC611) GGGAGAGGAGAGAACGUUCUACAGGCAAGGCAAUUGGGGAGUGUGGGUGGGGGGUCGAUCGAUCGAUCAUCGAUG SEQ ID NO 104 (ARC612) GGGAGAGGAGAGAACGUUCUACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGGGGUCGAUJCGAUCGAUCAUCGAUG 92 WO 2007/035922 PCT/US2006/037276 SEQ ID NO 105 (ARC614) GGGAGAGGAGAGAACGUUCUACAAGGCGGUACGGGGAGUGUGGGUUGGGGCCGGiCGAUCGAICGAUCAUCGAUG SEQ ID NO 106 (ARC616) GGGAGAGGAGAGAACGUUCUACGAUAUAGGCGGUACGGGGGGAGUGGGCUGGGGUCGAUCGAUCGAUCAUCGAUG SEQ ID NO 107 (ARC620) GGGAGAGGAGAGAACGUUCUACAGGAAAGGCGCUUGCGGGGGGUGAGGGAGGGGUCGAUCGAUCGAUCAUCGAUG SEQ ID NO 108 (ARC621) GGGAGAGGAGAGAACGUUCUACAGGCGGUUACGGGGGAUGCGGGUGGGACAGGUCGAUCGAUCGAUCAUCGAUG SEQ ID NO 109 (ARC626) GGGAGAGGAGAGAACGUUCUACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGGGUCGALICGAUCGAUCAUCGAUG SEQ ID NO 110 (ARC627) GGGAGAGGAGAGAACGUUCUACAGGCAAGUAALJUGGGGAGUGCGGGCGGGGUGUCGAUCGAUCGAUCAUCGAUG SEQ ID NO 111 (ARC628) GGGAGAGGAGAGAACGUUCUACAGGCAAGGCAAUUGGGGAGCGUGGGUGGGGGGGUCGAUCGALTCGAUCAUCGAUG SEQ ID NO 112 (ARC632) GGGAGAGGAGAGAACGUUCUACAAUUGCAGGUGGUGCCGGGGGUUGGGGGCGGGUCGAUCGAUCGAUCAUCGAUG SEQ ID NO 113 (ARC635) GGGAGAGGAGAGAACGUUCUACAGGCUCAAAAGAGGGGGAUGUGGGAGGGGGIJCGAUCGAUCGAUCAUCGAUG SEQ ID NO 114 (ARC642) GGGAGAGGAGAGAACGUUCUACAGGCGCAGCCAGCGGGGAGUGAGGGUGGGGGUCGAUCGAUCGAUCAUCGAUG SEQ ID NO 115 (ARC643) GGGAGAGGAGAGAACGUUCUACAGGCCGAUGAGGGGGAGCAGUGGGUGGGGGGUCGAUCGAUCGAUCAUCGAUG SEQ ID NO 116 ARC644) GGGAGAGGAGAGAACGUUCUACUAGUGAGGCGGUAACGGGGGGUGAGGGUGGGGUCGAUCGAUCGAUCAUCGAUG SEQ ID NO 117 (ARC645) GGGAGAGGAGAGAACGUUCUACAGGtAGGCAAGAUJAUUGGGGGAAGCGGGUGGGGUCGAUCGAICGAUCAUCGAUG SEQ ID NO 118 (ARC 646) GGGAGAGGAGAGAACGUUCUACACAUGGCUCGAAAGAGGGGCGUGAGGGUGGGGJCGAUCGAUCGAUCAUCGAUG [00287] Table 13: Summary of dRnY clone binding SEQ ARC # Selection

K

0 hIL- KD hIL 93 WO 2007/035922 PCT/US2006/037276 ID NO 23 (nM) 12 (nM) 103 ARC611 R7 hIL-23/12neg 21.3 123.1 104 ARC612 R7 hIL-23/12neg 5.8 41.7 105 ARC614 R7 hIL-23/12neg 3.1 54.4 106 ARC616 R7 hIL-23/12neg 13.1 52.1 107 ARC620 R7 hIL-23/12neg 44.8 178.7 108 ARC621 R7 IiIL-23/12neg 28.8 111.9 109 ARC626 R7 hIL-23S 10.1 69.8 110 ARC627 R7 hIL-23S 7 79.5 111 ARC628 R7 hIL-23S 57.8 146.5 112 ARC632 R7 hIL-23S 19.1 63.9 113 ARC635 R7 hIL-23S 171.5 430.9 114 ARC642 R7 hIL-23 37.2 188.3 115 ARC643 R7 hIL-23S 71.6 309.4 116 ARC644 R7 hIL-23 34.5 192.9 117 ARC645 R7 hIL-23 33.5 137.3 118 ARC646 R7 hIL-23 207.9 382.6 *30 min RT incubation for KD detennination in dot blot assay *1X PBS +0.lmg/mL tRNA, salmon sperm DNA, BSA reaction buffer Human IL-23 Aptamer Selections Summar [00288] The different selection conditions and strategies for IL-23 SELEX"' yielded several aptamers, stabilized and/or minimized, having different binding characteristics. The rRfY selected aptamers have affinities approximately in the 15 nM to 460 nM range, and prior to any post-SELEX" optimization, have cellular potentcy with IC 50 s approximately in the 50 nM-to 5 gM range. These can be further minimized with appropriate gains in binding characteristics and are expected to show increased potency in cell based assays. These aptamers also show the greatest distinction between IL-23, having a greater than hundred fold discrimination of IL-23 to IL-12. [00289] The aptamers obtained under the rRmY selection conditions have affinities ranging from approximately 8 nM to 3 pM. However, their cellular potency is lower than the rRfY aptamers' potency. As for the rGmH constructs a single point screen was done, but not carried any further because their extent of binding over background was not as good 94 WO 2007/035922 PCT/US2006/037276 as the rRmY clones. 48 crude rGmH clone transcriptions were used at a 1:200 dilution and 0.1 mg/mL tRNA was used as competitor. The average binding over background was only about 14%, whereas the rRmY clone's average in the same assay was about 30%, with 10 clones higher than 40 %. [002901 The dRmY selected aptamers have high affinities in the range of -3 nM to -200 nM, and prior to any post-SELEX" optimization, show a remarkable cellular potency with

IC

50 s in the range of-50 nM to -500 nM (described in Example 3 below). Some of these aptamers also have a distinction of approximately 4 fold for IL-23 to IL-12, which may be improved upon by further optimization. EXAMPLE 1E: Selections against mouse ("m")-IL-23 with 2'-F pyrimidine containing pools (rRfY) [00291] Introduction: Two selections strategies were used to identify aptamers to mIL-23 using a pool consisting of 2'-OH purine and 2'-F pyrimidine nucleotides (rRfY composition). The first selection strategy (mIL-23) was a direct selection against mIL-23. The second selection strategy (mIL-23S) was a more stringent selection, in which the initial rounds had lower concentrations of RNA and protein in an attempt to drive the selection towards higher affinity binders. Both selection strategies yielded aptamers to mIL-23. [00292] Selection: Two selections (mIL-23 and mIL-23S) began with incubation of 2x1014 molecules of 2'F pyrinidine modified pool with the sequence 5' GGAGCGCACUCAGCCAC-N40-UUUCGACCUCUCUGCUAGC 3' (ARC275) (SEQ ID NO 119), including a spike of y 2 P ATP 5' end labeled pool, with mouse IL-23 (isolated in house). The series of N's in the template (SEQ ID NO 119) can be any combination of nucleotides and gives rise to the unique sequence region of the resulting aptamers. [002931 In Round 1 of the mIL-23 selection, pool RNA was incubated with 50 poles of protein in a final volume of 100 RL for 1 hr at room temperature. In Round 1 of the mIL 23S selection, pool RNA was incubated with 65 pmoles of mIL-23 in a final volume of 1300 tL for 1 hr at room temperature. Selections were performed in 1X PBS buffer. RNA:mIL-23 complexes and free RNA molecules were separated using 0.45 pin nitrocellulose spin columns from Schleicher & Schuell (Keene, NH). The columns were pre-washed with 1 mL 1X PBS, and then the RNA:protein containing solutions were added to the columns and spun in a centrifuge at 2000 rpm for 1 minute. Buffer washes were 95 WO 2007/035922 PCT/US2006/037276 performed to remove nonspecific binders from the filters (Round 1, 2 x 500 pL IX PBS; in later rounds, more stringent washes of increased number and volume to enrich for specific binders), then the RNA:protein complexes attached to the filters were eluted with 2 x 200 pL washes (2 x 100 pL washes in later rounds) of elution buffer (7 M urea, 100 mM sodium acetate, 3 mM EDTA, pre-heated to 90'C). The eluted RNA was precipitated (40 pIg glycogen, 1 volume isopropanol). The RNA was reverse transcribed with the Thermoscript 1 RT-PCR system (Invitrogen, Carlsbad, CA) according to the manufacturer's instructions, using the 3' primer 5'GCTAGCAGAGAGGTCGAAA 3' (SEQ ID NO 121), followed by PCR amplification (20 mM Tris pH 8.4, 50 mM KCl, 2 mM MgC1 2 , 0.5pM of 5' primer 5'TAATACGACTCACTATAGGAGCGCACTCAGCCAC 3' (SEQ ID NO 120), 0.5 pM of 3' primer (SEQ ID 121), 0.5 mM each dNTP, 0.05 units/ptL Taq polymerase (New England Biolabs, Beverly, MA)). PCR reactions were done under the following cycling conditions: a) 94'C for 30 seconds; b) 60'C for 30 seconds; c) 72'C for 30 seconds. The cycles were repeated until sufficient PCR product was generated. The minimum number of cycles required to generate sufficient PCR product is reported in Table] 4 as the "PCR Threshold". [00294] The PCR templates were purified using the QlAquick PCR purification kit (Qiagen, Valencia, CA). Templates were transcribed using a3 2 P GTP body labeling overnight at 37'C (4% PEG-8000, 40 mM Tris pH 8.0, 12 mM MgC1 2 , 1 mM spennidine, 0.002 % Triton X-1 00, 3 mM 2'OH purines, 3 mM 2'F pyrimidines, 25 mM DTT, 0.25 units/100 pL inorganic pyrophosphatase, 2 pg/mL T7 Y639F single mutant RNA polymerase, 5uCi a 2 P GTP). [00295] Subsequent rounds were repeated using the same method as for Round 1, but with the addition of a negative selection step. Prior to incubation with protein target, the pool RNA was passed through a 0.45 micron nitrocellulose filter column to remove filter binding sequences, then the filtrate was carried on into the positive selection step. In alternating rounds the pool RNA was gel purified. Transcription reactions were quenched with 50 mM EDTA and ethanol precipitated then purified on a 1.5 mm denaturing polyacrylamide gels (8 M urea, 10% acrylamide; 19:1 acrylamide:bisaciylamide). Pool RNA was removed from the gel by passive elution in 300 mM NaOAc, 20 mM EDTA, followed by ethanol precipitation with the addition of 300 mM sodium acetate and 2.5 volumes of ethanol. 96 WO 2007/035922 PCT/US2006/037276 [00296] The RNA remained in excess of the protein throughout the selections (-1 PM RNA). The protein concentration was dropped to varying lower concentrations based on the particular selection. Competitor tRNA was added to the binding reactions at 0.1 mg/mL starting at Round 2 or 3, depending on the selection. A total of 7 rounds were completed, with binding assays performed at select rounds. Table 14 contains the selection details including pool RNA concentration, protein concentration, and tRNA concentration used for each round. Elution values (ratio of CPM values of protein-bound RNA versus total RNA flowing through the filter column) along with binding assays were used to monitor selection progress. [002971 Table 14: rRfY mIL-23 Selection conditions: 1. rRfY mIL-23 RNA pool protein Round conc conc tRNA PCR # (pM) (nM) neg (mg/mL) %elution Threshold 1 3.3 500 none 0 2.64 8 2 1 500 filter 0.1 4.24 8 3 -1 200 filter 0.1 0.73 10 4 1 200 filter 0.1 3.71 8 5 -1 100 filter 0.1 0.41 10 6 1 100 filter 0.1 9.27 8 7 -1 100 filter 0.1 0.87 9 2. rRfY mIL-23S (stringent) RNA pool protein Round conc conc tRNA PCR # (pM) (nM) neg (mg/mL) %elution Threshold 1 0.25 50 none 0 2.79 8 2 0.1 50 filter 0 4.14 8 3 -1 50 filter 0.1 0.16 11 4 1 50 filter 0.1 2.57 8 5 -1 25 filter 0.1 0.42 10 97 WO 2007/035922 PCT/US2006/037276 6 0.8 25 filter 0.1 10.29 8 7 ~1 25 filter 0.1 0.13 10 [00298] rRfY mIL-23 Protein Binding Analysis: Dot blot binding assays were performed throughout the selections to monitor the protein binding affinity of the pools as previously described. When a significant level of binding of RNA in the presence of mIL-23 was observed, the pools were cloned using a TOPO TA cloning kit (Invitrogen, Carlsbad, CA) according to the manufacturer's instructions. For both mIL-23 selections, the Round 7 pool templates were cloned, and 16 individual clones from each selection were assayed using an 8-point mIL-23 titration. Seven of the 32 total clones screened had specific binding curves and are listed below in Table 16. Table 15 lists the corresponding sequences. All others displayed nonspecific binding curves similar to the unselected naYve pool. Clones with high affinity to mIL-23 were subsequently screened for protein binding against mouse IL-12, human IL-23 and human IL- 12 in the same manner. [00299] The nucleic acid sequences of the rRfY aptamers characterized in Table 15 are given below. The unique sequence of each aptamer below begins at nucleotide 18, immediately following the sequence GGAGCGCACUCAGCCAC (SEQ ID NO 122), and runs until it meets the 3'fixed nucleic acid sequence UUUCGACCUCUCUGCUAGC (SEQ ID NO 123). [00300] Unless noted otherwise, individual sequences listed below are represented in the 5' to 3' orientation and represent the sequences that bind to mouse IL-23 selected under rRfY SELEX7 conditions wherein the purines (A and G) are 2'-OH and the pyrimidines (C and U) are 2'-fluoro. Each of the sequences listed in Table 15 may be derivatized with polyalkylene glycol ("PAG") moieties and may or may not contain capping (e.g., a 3' inverted dT). [00301] Table 15: mIL-23 rRfY Clone Sequences SEQ ID NO 124 (ARC1628) GGAGCGCACUCAGCCACAGGUGGCUUAAUACUGUAAAGACGUGCGCGCAAGGGAUUUUCGACCUCUCUGCUAGC SEQ ID NO 125 (ARC1629) GGAGCGCACLJCAGCCACCGUAAUUCACAAGGUCCCUGAGUGCAGGGUUGUAUGUUUGUUUCGACCUCUCUGCUAGC SEQ ID NO 126 (ARC1630) GGAGCGCACUCAGCCACUCUACUCGAUAUAGUUUAUCGAGCCGGUGGUAGAUUAUGAUUUCGACCUCUCUGCUAGC SEQ ID NO 127 (ARC1631) 98 WO 2007/035922 PCT/US2006/037276 GGAGCGCACUCAGCCACGCCUACAAUUCACUGUGAUAUALUCGAAUJUAUAGCCCUGGUUUCGACCUCUCUGCUAGC SEQ ID NO 128 (ARC1632) GGAGCGCACUCAGCCACCGGCUUAAUAUCCAAUAGGAACGUUCGCUCJGAGCAGGCGUUUCGACCUCUCUGCUAGC SEQ ID NO 129 (ARC1633) GGAGCGCACUCAGCCACAGCUCGGUGGCUUAAUAUCUAUGUGAACGUGCGCAACAGCUUUCGACCJCUCUGCUAGC SEQ ID NO 130 (ARC1634) GGAGCGCACUCAGCCACCUUGGGCUUAAUACCUAUCGGAUGUGCGCCUAGCACGGAAUUUCGACCUCUCJGCUAGC [00302] Table 16: rnIL-23 rRfY Clone binding activity SEQ ID KD mIL-23 KD mIL-12 KD hIL-23 KD hIL NO Clone Name Selection (nM) (nM) (UM) 12 (nM) 124 ARC1628 R7 mIL-23 2 6 52 16: 125 ARC1629 R7 mIL-23 34 103 31 7 126 ARC1630 R7 mIL-23S 14 18 65 23 127 ARC1631 R7 mIL-23S 33 72 39 6S 128 ARC1632 R7 mIL-23S 13 16 91 18( 129 ARC1633 R7 mIL-23S 17 44 79 19, 130 ARC1634 R7 mIL-23S 3 29 39 62 *30min RT incubation for KD determination *1X PBS +0.1mg/mL BSA reaction buffer EXAMPLE 1F: Selections for mouse IL-23 aptamers with specificity against mouse IL-12 [00303] Introduction. One selection was performed to identify aptamers to mouse-IL-23 (mIL-23) with specificity against mouse IL- 12 (mIL- 12). This selection was split off from the rRfY selection mIlL-23S described in the above section starting at Round 3. This selection yielded aptamers to niIL-23 that had -3-5-fold specificity over mIL-12. mIL-23S/mIL-12 neg rRfY Selection. To obtain mouse IL-23 aptamers with specificity against mouse IL-12, mouse IL-12 was included in a negative selection, similar to the protein in negative (PN-IL-23) selection described above in Example 1A. The resultant RNA from Round 2 of the mIL-23S selection described in Example 1E above was used to start the R3PN mIL-23/12neg selection, in which mIL- 12 was included in the negative step of selection. Nine rounds of selection were performed, with binding assays performed at select rounds. Table 17 summarizes the selection conditions including pool RNA concentration, protein concentration, and tRNA concentration used for each round. Elution 99 WO 2007/035922 PCT/US2006/037276 values (ratio of CPM values of protein-bound RNA versus total RNA flowing through the filter column) along with binding assays were used to monitor selection progress. [00304] Table 17: rRfY mIL-23S/mIL-12 neg Filter Selection Summary RNA neg pool protein mIL12 PCR Round cone conc tRNA conc cycle # (pM) (nM) neg (mg/mL) (nM) %elution # 1 0.25 50 none 0 0 2.79 8 2 0.1 50 filter 0 0 4.14 8 3 ~1 500 filter/IL12 0.1 250 1.33 10 4 1 500 filter/IL12 0.1 500 1.68 8 5 1 250 filter/IL12 0.1 250 0.89 9 6 1 200 filter/IL12 0.1 200 1.47 8 7 1 150 filter/IL12 0.1 150 1.39 8 8 1 150 filter/IL12 0.1 150 3.73 8 9 1 150 filter/IL12 0.1 150 2.98 8 Selection buffer: IX PBS *1 hr positive incubation [00305] rRfY mIL-23 S/mIL- 12 neg Protein Binding Analysis. The dot blot binding assays previously described were perfonned throughout the selection to monitor the protein binding affinity of the pool. Trace 32P-labeled RNA was combined with mIL-23 or mIL- 12 and incubated at room temperature for 30 min in 1X PBS plus 0. 1mg/mL BSA for a final volume of 30 piL. The reaction was added to a dot blot apparatus (Schleicher and Schuell Minifold- 1 Dot Blot, Acrylic). Binding curves were generated as described in previous sections. When a significant level of binding of RNA in the presence of mIL-23 was observed, the pool was cloned using the TOPO TA cloning kit (Invitrogen, Carlsbad, CA) according to the manufacturer's instructions. The Round 9 pool template was cloned, and 10 individual clones from the selection were assayed in an 8-point dot blot titration against mIL-23. Clones that bound significantly to mIL-23 were then screened for binding to mIL 12. Table 18 sununarizes protein binding characterization of the binding clones. Four of the 10 total clones screened bound specifically to mIL-23 and mIL- 12 at varying affinities. All other clones displayed nonspecific binding curves similar to the unselected naYve pool. The sequences for the four binding clones are listed in Table 19 below. 100 WO 2007/035922 PCT/US2006/037276 [00306] Table 18: rRfY mIL-23S/mIL-12 neg Clone binding activity SEQ ID NO KD mIL-23 KD mIL-12 Clone Name (nM) (nM) 131 AMX369.F1 63 165 132 AMX369.H1 23 194 133 AMX369.B2 49 252 134 AMX369.G3 106 261 *30min RT incubation for KD detennination *1X PBS +0.1mg/nL BSA reaction buffer [003071 The nucleic acid sequences of the rRfY aptamers characterized in Table 19 are given below. The unique sequence of each aptamer below begins at nucleotide 18, immediately following the sequence GGAGCGCACUCAGCCAC (SEQ ID NO 122), and runs until it meets the 3'fixed nucleic acid sequence UUUCGACCUCUCUGCUAGC (SEQ ID NO 123). [00308] Unless noted otherwise, individual sequences listed below are represented in the 5' to 3' orientation and represent the sequences that bind to mouse IL-23 selected under rRfY SELEX. conditions wherein the purines (A and G) are 2'-OH and the pyrimidines (U and C) are 2'-fluoro. Each of the sequences listed in Table 19 may be derivatized with polyalkylene glycol ("PAG") moieties and may or may not contain capping (e.g., a 3' inverted dT). [003091 Table 19: rRfY mIL-23S/mIL-12 neg Sequence Information SEQ ID NO 131 (AMX(369)_F1) GGAGCGCACUCAGCCACGGULUACUUCCGUGGCAAUAUGACCUCNCUCUAGACAGGUUUCGACCUCUCUGCUAGC SEQ ID NO 132 (AMX(369) H1) (ARC 1914) GGAGCGCACUCAGCCACCUGGGAAAAUCUGGGUCCCUGAGUUCUAACAGCAGAGAUUUUUCGACCUCUCUGCUAGC SEQ ID NO 133 (AMX(369)_B2) GGAGCGCACUCNGCCACUUCGGAAUAUCGUUGUCUUCUGGGUGAGCAUGCGUUGAGGUUUCNACCUCUCUGCUAGC SEQ ID NO 134 (AMX(369)_G3) GGAGCGCACUCAGCCACUGGGGAACAUCUCAUGUCUCUGACCGCUCUUGCAGUAGAAUUUNGACCUCUCUGCUAGC 101 WO 2007/035922 PCT/US2006/037276 EXAMPLE 2: COMPOSITION AND SEQUENCE OPTIMIZATION AND SEQUENCES EXAMPLE 2A: Minimization [003101 Following a successful selection and following the determination of sequences of aptamers, in addition to determination of functionality in vitro, the sequences were minimized to obtain a shorter oligonucleotide sequence that retained binding specificity to its intended target but had improved binding characteristics, such as improved KD and/or

IC

50 s. Example 2A. 1: Minimization of rRfY Clones: [00311] The binding parent clones from the rRfY selection described in Example 1A fell into two principal families of aptamers, referred to as Type 1 and Type 2. Figure 8A and 8B show examples of the sequences and predicted secondary structure configurations of Type 1 and Type 2 aptamers. Figure 9A and 9B show the minimized aptainer sequences and predicted secondary structure configurations for Types 1 and 2. [003121 On the basis of the IL-23 binding analysis described in Example 1 above and the cell based assay data described in Example 3 below, several Type 1 clones from the rRfY PN-IL-23 selection including AMX84-A1O (SEQ ID NO 43), AMX84-B10 (SEQ ID NO 44), and AMX84-F 11 (SEQ ID NO 46) were chosen for further characterization. Minimized DNA construct oligonucleotides were transcribed, gel purified, and tested in dot blot assays for binding to h-IL-23. [00313] The minimized clones AlOmin5 (SEQ ID NO 139), Al0min6 (SEQ ID NO 140) were based on AMX84-A1O (SEQ ID NO 43), the minimized clones Bl0min4 (SEQ ID NO 144), and B1Omin5 (SEQ ID NO 145) were based on AM.X84-B10 (SEQ ID NO 44), and the minimized clone F 11min2 (SEQ ID NO 147), was based on AMX84-F1 1 (SEQ ID NO 46) (Figure 9A). The clones were 5'end labeled with y- 32 P ATP, and were assayed in dot blot assays for KD determination using the same method as for the parent clones. All had significant protein binding (summarized in Table 21), and each was more potent than the respective parent clones from which they are derived when tested in cell based assays as discussed in Example 3 below. [003141 Additionally, minimized constructs exemplifying Type 1 and Type 2 aptamers were made and tested based on the concensus sequence of Type 1 and Type 2 aptamer sequence families. Typel.4 (SEQ ID NO 151), and Type1.5 (SEQ ID NO 152) are two 102 WO 2007/035922 PCT/US2006/037276 examples of such minimized constructs based on the Type 1 family sequence, which displayed high IL-23 binding affinity and the most potent activity in the cell based assay described in Example 3, as compared to the other Type 1 minimers described above. [003151 The resulting rRfY minimers' sequences are listed in Table 20 below. Table 21 shows the minimer binding data for the minimers listed in Table 20. [00316] For the minimized rRfY aptamers described in Table 20 below, the purines (A and G) are 2'-OH purines and the pyrimidines (C and U) are 2'-fluoro pyrimidines. Unless noted otherwise, the individual sequences are represented in the 5' to 3' orientation. Each of the sequences listed in Table 20 may be derivatized with polyalkylene glycol ("PAG") moieties and may or may not contain capping (e.g., a 3'-inverted dT). [003171 Table 20 - PN-IL-23 2' F (rRfY) Minimer Aptamer sequences. SEQ ID NO 135 (A10.minl) GGAGAUCAUACACAAGAAGUUUUUUGUGCUCUGAGUACUCAGCGUCCGUAAGGGAUCUCC SEQ ID NO 136 (AlO.min2) GGAGUCUGAGUACUCAGCGUCCGUAAGGGAUAUGCUCCGCCAGACUCC SEQIDNO 137 (A1O.min3) GGAGUUACUCAGCGUCCGUAAGGGAUAUGCUCCGACUCC SEQ ID NO 138 (A1O.min4) GGAGUCUGAGUACUCAGCGUCCCGAGAGGGGAUAUGCUCCGCCAGACUCC SEQ ID NO 139 (A1O.min5) GGAGCAUACACAAGAAGUUUUUJUGUGCUCUGAGUACUCAGCGUCCGUAAGGGAUAUGCUCC SEQ ID NO 140 (A10.min6) GGAGUACGCCGAAAGGCGCUCUGAGUACUCAGCGUCCGUAAGGGAUACUCC SEQ ID NO 141 (B1O.minl) GGAGCGAAUCAUACACAAGAAGUGCUUCAUGCGGCAAACUGCAUGACGUCGAAUAGAUAUGCUCC SEQ ID NO 142 (BO.min2) GGAUCAUACACAAGAAGUGCUUCAUGCGGCAAACUGCAUGACGUCGAAUAGAUCC SEQ ID NO 143 (BlO.min3) GGAUCAUACACAAGAAGUGCUUC'ACGAAAGUGACGUCGAAUAGAUCC SEQ ID NO 144 (B10.min4) GGAGCAUACACAAGAAGUGCUUCAUGCGGCAAACUGCAUGACGUCGAAUAGAUAUGCUCC 103 WO 2007/035922 PCT/US2006/037276 SEQ ID NO 145 (B1O.MIN5) GGAGUACACAAGAAGUGCUUCCGAAAGGACGUCGAAUAGAUACUCC SEQ ID NO 146 (F11.minl) GGUUAAAUCUCAUCGUCCCCGUUUGGGGAU SEQ ID NO 147 (Fl 1.min2) GGACAUACACAAGAUGUGCUUGAGUUAAAUCUCAUCGUCCCCGUUUGGGGAUAUGUC SEQ ID NO 148 (Type 1.1) GGCAUACACGAGAGUGCUGUCGAAAGACUCGGCCGAGAGGCUAUGCC SEQ ID NO 149 (Typel.2) GGCAUACGCGAGAGCGCUGGCGAAAGCCUCGGCCGAGAGGCUAUGCC SEQ IDNO 150 (Typel.3) GGAUACCCGAGAGGGCUGGCGAAAGCCUCGGCGAGAGCUAUCC SEQ ID NO 151 (Typel.4) GGGUACGCCGAAAGGCGCUUCCGAAAGGACGUCCGUAAGGGAUACCC SEQ ID NO 152 (Type l.5) GGAGUACGCCGAAAGGCGCUUCCGAAAGGACGUCCGUAAGGGAUACUCC SEQ ID NO 153 (Type 2.1) GGAAUCAUACCGAGAGGUAUUACCCCGAAAGGGGACCAUUCC SEQ ID NO 154 (D9.1) GGAAUCAUACACAAGAGUGUAUUACCCCCAACCCAGGGGGACCAUUCC SEQ ID NO 155 (C11.1) GGAAGAAUGGUCGGAAUCUCUGGCGCCACGCUGAGUAUAGACGGAAGCUCCGCCAGA SEQ ID NO 156 (C11.2) GGAGGCGCCACGCUGAGUAUAGACGGAAGCUCCGCCUCC SEQ ID NO 157 (C10.1) GGACACAAGAGAUGUAUUCAGGCGGUCCGCAUUGAUGUCAGUUAUGCGUAGCUCCGCC SEQ ID NO 158 (C1O.2) GGCGGUCCGCAUUGAUGUCAGUUAUGCGUAGCUCCGCC 104 WO 2007/035922 PCT/US2006/037276 [003181 Table 21 - PN-IL-23 rRfY Minimer Binding data SEQ ID Clone +/-IL-23 20 +/-IL-23 100 IL-23 KD No. Description UM nM (nM) 135 AlOmin 2.2 3.1 136 Al0min2 4.4 6.0 137 Al0min3 0.8 1.6 138 A1Omin4 0.9 0.7 146 FlminI 0.8 0.6 147 Fllmin2 7.8 16.9 65 141 BlOminI 7.5 33.9 142 B10min2 1.3 1.6 143 BlOmin3 0.6 0.8 139 AlOmin5 12.8 40.9 57.8 140 AlOmin6 13.6 41.7 48.3 144 BlOmin4 39.4 122.1 36.4 145 BlOmin5 20.7 89.2 276.9 148 IL-23 Type 1.1 1.4 0.9 149 IL-23 Type 1.2 0.8 0.7 150 IL-23 Type 1.3 0.8 0.6 153 IL-23 Type 2.1 1.7 5.2 154 D9.1 1.2 3.9 155 C11.1 1.0 3.5 156 C11.2 1.1 2.3 157 C10.1 1.4 4.4 158 C10.2 1.4 1.5 151 IL-23 Type 1.4 2.3 11.7 185.3 152 IL-23 Type 1.5 5.2 26.9 31.4 **Assays performed +0. 1mg/mL tRNA, 30min RT incubation **R&D IL-23 (carrier free protein) Example 2A.2: Minimization of dRmY Selection 1: [00319] Following the dRmY selection process for aptamers binding to IL-23 (described in Example 1C above) and determination of the oligonucleotide sequences, the sequences were systematically minimized to obtain shorter oligonucleotide sequences that retain the 105 WO 2007/035922 PCT/US2006/037276 binding characteristics. On the basis of the IL-23 binding analysis described in Example 1A above and the cell based assay data described in Example 3 below, ARC489 (SEQ ID NO 91) (74mer) was chosen for further characterization. 3 minimized constructs based on clone ARC489 (SEQ ID NO 91) were designed and generated. The clones were 5'end labeled with y- 32 P ATP, and were assayed in dot blot assays for KD determination using the same method as for the parent clones in 1X PBS +0.1 mg/mL tRNA, 0.1 mg/mL salmon sperm DNA, 0.1 mg/mL BSA, for a 30 minute incubation at room temperature. Table 22 shows the sequences for the minimized dRmY aptamers. Table 23 includes the binding data for the dRmY minimized aptamers. Only one minimized clone, ARC527 (SEQ ID NO 159), showed binding to IL-23. This clone was tested in the TransAM" STAT3 activation assay described in Example 3 below, and showed a decrease in assay activity compared to its respective parent, ARC489 (SEQ ID NO 91). [003201 For the minimized dRmY aptamers described in Table 22 below, the purines (A and G) are deoxy-purines and the pyrimidines (U and C) are 2'-OMe pyrimidines. Unless noted otherwise, the individual sequences are represented in the 5' to 3' orientation. Each of the sequences listed in Table 22 may be derivatized with polyalkylene glycol ("PAG") moieties and may or may not contain capping (e.g., a 3'-inverted dT). [00321] Table 22: Sequences of dRmY Minimized SEQ ID NO 159 (ARC527) ACAGCGCCGGUGGGCGGGCAUUGGGUGGAUGCGCUGU SEQ ID NO 160 (ARC528) GCGCCGGUGGGCGGGCACCGGGUGGAUGCGCC SEQ ID NO 161 (ARC529) ACAGCGCCGGUGUUUUCAUUGGGUGGAUGCGCUGU [00322] Table 23: Binding characterization of dRmY selection 1 minimers SEQ ID NO Clone Name KD (nM) SEQ ID 159 ARC 527 12.6 SEQID160 ARC528 NB SEQID161 ARC529 NB **R&D IL-23 (carrier free protein) N.B.= no binding detectable 106 WO 2007/035922 PCT/US2006/037276 Example 2A.3: Minimization of dRmY Selection 2: [00323] Following the dRmY selection process for aptamers binding to IL-23 (described in Example 1 D above) and determination of the oligonucleotide sequences, the sequences were systematically minimized to obtain shorter oligonucleotide sequences that retain the binding characteristics [00324] Based on sequence analysis and visual inspection of the parent dRnY aptamer sequences described in Example 1D, it was hypothesized that the active conformation of dRmY h-IL-23 binding clones and their minimized constructs fold into a G-quartet structure (Figure 10). Analysis of the functional binding sequences revealed a pattern of G doubles consistent with a G quartet formation (Table 24). The sequences within the G quartet family fell into 2 subclasses, those with 3 base pairs in the l't stem and those with 2. It has been reported that in much the same way that ethidium bromide fluorescence is increased upon binding to duplex RNA and DNA, that N-methylmesoporphyrin IX (NMM) fluorescence is increased upon binding to G-quartet structures (Arthanari et al., Nucleic Acids Research, 26(16): 3724 (1996); Marathais et al., Nucleic Acids Research, 28(9): 1969 (2000); Joyce et al., Applied Spectroscopy, 58(7): 831 (2004)). Thus as shown in Figure 11, NMM fluorescence was used to confirm that ARC979 (SEQ ID NO 177) does in fact adopt a G-quartet structure. According to the literature protocols, 100 microliter reactions containing -1 micromolar NMM and ~ 2 micromolar aptamer in Dulbecco's PBS containing magnesium and calcium were analyzed using a SpectraMax Gemini XS fluorescence plate reader. Fluorescence emission spectra were collected from 550 to 750 un with and excitation wavelength of 405 mn. The G-quartet structure of the anti-thrombin DNA aptamer ARC183 (Macaya et al., Proc. Natl. Acad. Sci., 90: 3745 (1993)) was used as a positive control in this experiment. ARC 1346 is an aptamer of a similar size and nucleotide composition as ARC979 (SEQ ID NO 177) that is not predicted to have a G quartet structure and was used as a negative control in the experiment. As can be seen in Figure 11, ARC 183 and ARC979 (SEQ ID NO 177) show a significant increase in NMM fluorescence relative to NMM alone while the negative control, ARC 1346 does not. [00325] Minimized constructs were synthesized on an ABI EXPEDITETM DNA synthesizer, then deprotected by standard methods. The minimized clones were gel purified on a 10% PAGE gel, and the RNA was passively eluted in 300 mM NaOAc and 20 mM EDTA, followed by ethanol precipitation. 107 WO 2007/035922 PCT/US2006/037276 [003261 The clones were 5 'end labeled with y- 32 P ATP, and were assayed in dot blot assays for KD determination using the direct binding assay in which the aptamer was radio labeled and held at a trace concentration (< 90 pM) while the concentration of IL-23 was varied, in IX PBS with 0.1 mg/mL BSA, for a 30 minute incubation at room temperature. The fraction aptamer bound vs. [IL-23] was used to calculate the KD by fitting the following equation to the data: Fraction aptamer bound = amplitude*([IL-23]/(KD + [IL-23])) + background binding. [003271 Several of the minimized constructs from the dRmY Selection 2 were also assayed in a competition format in which cold aptamer was titrated and competed away trace 3P ATP labeled aptamer In the competition assay, the [IL-23] was held constant, the [trace labeled aptamer] was held constant, and the [unlabeled aptamer] was varied. The KD was calculated by fitting the following equation to the data: Fraction aptamer bound = amplitude*([aptamer]/( KD + [aptamer])) + background binding. [00328] Minimers based upon the G quartet were functional binders, whereas minimers based on a folding algoritlun that predicts stem loops (RNAstructure; D.H. Mathews, et al., "Expanded Sequence Dependence of Thermodynamic Parameters Improves Prediction of RNA Secondary Structure". Journal of Molecular Biology, 288, 911-940, (1999)) and that did not contain the pattern of G doubles were non functional (ARC793 (SEQ ID NO 163)). [00329] Table 25 below summarizes the minimized sequences and the parent clone from which they were derived, and Table 26 summarizes the binding characterization from direct binding assays (+/- tRNA) and competition binding assays for the minimized constructs tested. [003301 Table 24: Aligmnent of functional clones. (only the regions within the G quartet are represented) 108 WO 2007/035922 PCT/US2006/037276 AMX(185) C2 = arc 626 GG-CAA-G-TAA--TTG-GG-GAGTG-C--GG-GCGG-GG 28 AMX(185) G3 = arc 627 GG-CAA-G-TAA--TTG-GG-GAGTG-C--GG-GCGG-GG 28 AMX(184) H9 = arc 612 GG-CAA-G-TAA--TTG-GG-GAGTG-C--GG-GCGG-GG 28 AMX(184) G9 = arc 611 GG-CAA-GGCAA--TTG-GG-GAGTG-T--GG-GTGG-GG 29 AMX(184) G6 = arc 645 GG-CAA-GAT-A--TTG-GG-GGAAG-C--GG-GTGG-GG 28 AMX(185) B2 = arc 628 GG-CAA-GGCAA--TTG-GG-GAGCG-T--GG-GTGG-GG 29 AMX(184) A9 = arc 621 GG-CG--G-TTA - CG-GG-GGATG-C--GG-GTG--GG 25 AMX(184) C4 = arc 644 GG-CG--G-TAA---CG-GG-GGGTG-A--GG-GTGG-GG 26 AMX(184) F10 = arc 616 GG-CG--G-T-A-- CG-GG-GGGAG-T--GG-GCTG-GG 25 AMX(184) _Eli = arc 614 GG-CG--G-T-A-- CG-GG-GAGTG-T--GG-GTTG-GG 25 AMX(185) _A6 =arc 643 GG-CC--GATGA---GG-GG-GAGCAGT--GG-GTGG-GG 28 AMX(184) _A8 = arc 620 GG-CGC---TT---GCG-GG-GGGTG-A--GG-GAGG-GG 26 AMX(184) _H3 = arc 646 GG-CTC-GA-AA--GAG-GG-GCGTG-A--GG-GTGG-GG 28 AMX(185) _G5 = arc 635 GG-CTC-AA-AA--GAG-GG-GGATG-T--GG-GAGG-GG 28 AMX(184) A4 = arc 642 GG-CGC-AGC-A--GCG-GG-GAGTG-A--GG-GTGG-GG 29 AMX(185)_D1 = arc 632 GG-TGG--- T-G--CCG-GG-GGTTG---- GG-GGCG-GG 25 [003311 The SEQ ID NOS for the clones listed in Table 24 are found in Table 12. [00332] For the minimized dRmY aptamers described in Table 25 below, the purines (A and G) are deoxy-purines and the pyrimidines (C and U) are 2'-OMe pyrimidines. Unless noted otherwise, the individual sequences are represented in the 5' to 3' orientation. Each of the sequences listed in Table 25 may be derivatized with polyalkylene glycol ("PAG") moieties and may or may not contain capping (e.g., a 3'-inverted dT). [00333] Table 25: dRmY minimer sequences SEQ Parent ID Clone NO Minimer Minimized Sequence 162 ARC 627 ARC792 GGCAAGUAAUUGGGGAGUGCGGGCGGGG 163 ARC 614 ARC793 CUACAAGGCGGUACGGGGAGUGUGG 164 ARC 614 ARC794 GGCGGUACGGGGAGUGUGGGUUGGGGCCGG 165 ARC 616 ARC795 CGAUAUAGGCGGUACGGGGGGAGUGGGCUGGGGUCG 166 ARC 626 ARC796 UAAUUGGGGAGUGCGGGCGGGGGGUCGAUCG 167 ARC 626 ARC797 GGUGGGGAGUGCGGGCGGGGGGUCGCC 168 ARC 627 ARC889 ACAGGCAAGGUAAUUGGGGAGUGCGGGCGGGGUGU 169 ARC 627 ARC890 CCAGGCAAGGUAAUUGGGGAGUGCGGGCGGGGUGG 109 WO 2007/035922 PCT/US2006/037276 170 ARC 627 ARC891 GGCAAGGUAAUUGGGAAGUGUGGGCGGGG 171 ARC 627 ARC892 GGCAAGGUAAUUGGGUAGUGAGGGCGGGG 172 ARC 627 ARC893 GGCAAGGUAAUUGGGGAGUGCGGGCUGGG 173 ARC 627 ARC894 GGCAAGGUAAUUGGGAAGUGUGGGCUGGG 174 ARC 627 ARC895 GGCAAGGUAAUUGGGUAGUGAGGGCUGGG 175 ARC 627 ARC896 ACAGGCAAGGUAAUUGGGUAGUGAGGGCUGGGUGU 176 ARC GAUGUUGGCAAGUAAUUGGGGAGUGCGGGCGGGGUUCA 627 ARC897 UC-3T 177 ARC 627 ARC979 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 178 ARC 627 ARC980 CCAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGG 179 ARC 621 ARC981 GGCGGUUACGGGGGAUGCGGGUGGG 180 ARC 621 ARC982 GGCGGUUACGGGGGAUGCGGGUGGGACAGG 181 ARC ARC111 627 7 GGCAAGUAAUUGGGGAGUGCGGGCGG 182 ARC ARC111 627 8 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGUGU 183 ARC ARC111 614 9 GGCGGUACGGGGAGUGUGGGUUGGGGCC 184 ARC ARC112 614 0 GGCGGUACGGGGAGUGUGGGCUGGGGCC 185 ARC ARC112 614 1 GGUACGGGGAGUGUGGGUUGGG 186 ARC ARC112 614 2 GGUACGGGGAGUGUGGGCUGGG 187 ARC ARC112 614 3 GGCGGUACGGGGAGUGUGGGUUGGGCC 188 ARC ARC112 614 4 GGCGGUACGGGGAGUGUGGGCUGGGCC 189 ARC ARC112 614 5 GGUACGGGGAGUGUGGGUUGG 190 ARC ARC112 614 6 GGUACGGGGAGUGUGGGCUGG 191 ARC ARC112 GGCGGUACGGGGGGAGUGGGCUGGGGUC 110 WO 2007/035922 PCT/US2006/037276 616 7 192 ARC ARC112 616 8 GGCGGUACGGGGGGAGUGGGCUGGGUC 193 ARC ARC112 616 9 GGCGGUACGGGGAGAGUGGGCUGGGGUC 194 ARC ARC113 616 0 GGUACGGGGGGAGUGGGCUGGG 195 ARC ARC113 616 1 GGUACGGGGGGAGUGGGCUGG 196 ARC ARC113 616 2 GGUACGGGGAGAGUGGGCUGGG 197 ARC ARC117 616 0 GGCGGUACGGGGGGAGUGGGCUGGG 198 ARC ARC117 614 1 GGCGGUACGGGGAGUGUGGGUUGGG [00334] Table 26: protein binding characterization of dRmY minimers SEQ KD KD ID Minimer (+tRNA) KD (-tRNA) (competition) NO ARC# nM UM nM 162 ARC792 117 11 164 ARC794 69 14 165 ARC795 40 4 166 ARC796 106 167 ARC797 50 168 ARC889 115 169 ARC890 114 170 ARC891 177 171 ARC892 255 172 ARC893 2857 173 ARC894 no binding 174 ARC895 no binding 175 ARC896 no binding 176 ARC897 93 177 ARC979 93 90 9 178 ARC980 139 111 WO 2007/035922 PCT/US2006/037276 179 ARC981 no binding 180 ARC982 no binding 181 <parent ARC1117 clone 182 <parent ARC1118 clone 183 <parent ARC1119 clone 184 <parent ARC 1120 clone 185 <parent ARC1121 clone 186 <parent ARC1122 clone 187 <parent ARC 1123 clone 188 <parent ARC 1124 clone 189 <parent ARC1125 clone 190 <parent ARC1126 clone 191 <parent ARC1127 clone 192 <parent ARC1 128 clone 193 <parent ARC 1129 clone 194 <parent ARC1130 clone 195 <parent ARC1131 clone 196 <parent ARC1132 clone 197 ARC 1170 no binding 198 ARC1171 no binding [003351 The competitive binding data was re-analyzed in a saturation binding experiment where the concentration of ligand (aptamer) was varied and the concentration of receptor 112 WO 2007/035922 PCT/US2006/037276 (IL-23) was held constant and the [bound aptaner] was plotted versus the [total input aptamer]. ARC979 (SEQ ID NO 177) was used in this analysis. [003361 The [ARC979] bound saturated at ~ 1.7 nM (Figure 12), which suggested that the concentration of IL-23 that was competent to bind aptamer was 1 nM, or 2 % (1/50) of the input IL-23. The calculated KD value was 8 nM, which agreed well with the value obtained by fitting the data represented in competition mode (8.7 nM). [00337] When IL-12 competition binding data was subjected to the same analysis (Figure 13), the fraction active IL-12 was higher (10%), and the specificity of ARC979 for IL-23 vs. IL- 12 (33-fold) was greater than what was predicted by the direct binding measurements (2 - 5 fold). [00338] Subsequently, the direct binding assay was repeated for ARC979 using the binding reaction conditions described previously (lX PBS with 0.1 mg/mL BSA for 30 minute incubation at room temperature) and using different binding reaction conditions (IX Dulbecco's PBS (with Mg ++ and Ca **) with 0.1 mg/ mL BSA for 30 minutes at room temperature). In both, newly chemically synthesized aptamers were purified using denaturing polyacrylamide gel electrophoresis, 5'end labeled withy- 2P ATP and were tested for direct binding to full human IL-23. An 8 point protein titration was used in the dot blot binding assay (either {100 nM, 30 nM, 10 nM, 3 nM, 1 nM, 300 pM, 100 pM, 0 pM} or {10 nM, 3 nM, 1 nM, 300 pM, 100 pM, 30 pM, 10 pM, 0 pM}). KD values were calculated by fitting the equation y= (max/(l+K/protein))+yint using KaleidaGraph (KaleidaGraph v. 3.51, Synergy Software). The buffer conditions appeared to affect the binding affinity somewhat. Under the 1X PBS condition, the KD value for ARC979 was calculated to be - 10 nM, whereas under the 1X Dulbecco's PBS condition, the KD value for ARC979 was calculated to be -1 nM. (see Figure 14). These KD values were verified in subsequent assays (data not shown), and are consistent with the IC 50 value of - 6 nM that ARC979 yields in the PHA Blast assay described below in Example 3D. Example 2A.4: Mouse IL-23 rRfY Minimization [00339] Based on visual inspection of the parent clone sequences of the mouse IL-23 rRfY aptamers described in Example 1E, and predicted RNA structures using an RNA folding program (RNAstructure), minimized constructs were designed for each of the seven binding mIL-23 clones. PCR templates for the minimized construct oligos were ordered 113 WO 2007/035922 PCT/US2006/037276 from Integrated DNA Technologies (Coraville, IA). Constructs were PCR amplified, transcribed, gel purified, and tested for binding to mIL-23 using the dot blot binding assay previously described. Trace 32 P-labeled RNA was combined with mIL-23 and incubated at room temperature for 30 min in IX PBS plus 0.1 mg/mL BSA for a final volume of 30 pL. The reaction was added to a dot blot apparatus (Schleicher and Schuell Minifold-1 Dot Blot, Acrylic). Binding curves were generated as described in previous sections. Table 32 lists the sequences of the mIL-23 binding minimized constructs. Table 33 summarizes the protein binding characterization for each rRfY minimized construct that had significant binding to mIL-23. [003401 Unless noted otherwise, individual sequences listed below are represented in the 5' to 3' orientation and represent the sequences that bind to mouse IL-23 selected under rRfY SELEX7 conditions wherein the purines (A and G) are 2'-OH and the pyrimidines (U and C) are 2'-fluoro. Each of the sequences listed in Table 32 may be derivatized with polyalkylene glycol ("PAG") moieties and may or may not contain capping (e.g., a 3' inverted dT). [00341] Table 32 minimized mouse rRfY clone sequences SEQ ID NO 199 (ARC 1739) GGGCACUCAGCCACAGGUGGCLTUAAUACUGUAAAGACGUGCCC SEQ ID NO 200 (ARC 1918) GGAGCGCACUCAGCCACCGGCUUAAUAUCCAAUAGGAACGUUCGCUCU SEQ ID NO 201 GGGCACUCAGCCACAGCUCGGUGGCULJUAAUAUCUALIGUGAACGUJGCCC SEQ ID NO 202 GGGCACUCAGCCACCUUGGGCUUAAUACCUAUCGGAUGUGCCC [003421 Table 33: mIL-23 rRfY Clone KD Summary Minimized Parent Clone Parent Clone Clone KD mIL-23 SEQ ID NO Name SEQ ID NO (nM) 199 ARC1628 124 1 200 ARC1632 128 1 201 ARC1633 129 25 202 ARC1634 130 19 *30min RT incubation for KD determination *lX PBS +0.1mg/mL BSA reaction buffer 114 WO 2007/035922 PCT/US2006/037276 EXAMPLE 2B: Optimization through Medicinal Chemistry [00343] Aptamer Medicinal Chemistry is an aptamer improvement technique in which sets of variant aptamers are chemically synthesized. These sets of variants typically differ from the parent aptamer by the introduction of a single substituent, and differ from each other by the location of this substituent. These variants are then compared to each other and to the parent. Improvements in characteristics may be profound enough that the inclusion of a single substituent may be all that is necessary to achieve a particular therapeutic criterion. [00344] Alternatively the information gleaned from the set of single variants may be used to design further sets of variants in which more than one substituent is introduced simultaneously. In one design strategy, all of the single substituent variants are ranked, the top 4 are chosen and all possible double (6), triple (4) and quadruple (1) combinations of these 4 single substituent variants are synthesized and assayed. In a second design strategy, the best single substituent variant is considered to be the new parent and all possible double substituent variants that include this highest-ranked single substituent variant are synthesized and assayed. Other strategies may be used, and these strategies may be applied repeatedly such that the number of substituents is gradually increased while continuing to identify further-improved variants. [00345] Aptamer Medicinal Chemistry is most valuable as a method to explore the local, rather than the global, introduction of substituents. Because aptamers are discovered within libraries that are generated by transcription, any substituents that are introduced during the SELEX" process must be introduced globally. For example, if it is desired to introduce phosphorothioate linkages between nucleotides then they can only be introduced at every A (or every G, C, T, U etc.) (globally substituted). Aptamers which require phosphorothioates at some As (or some G, C, T, U etc.) (locally substituted) but cannot tolerate it at other As cannot be readily discovered by this process. [00346] The kinds of substituent that can be utilized by the Aptamer Medicinal Chemistry process are only limited by the ability to generate them as solid-phase synthesis reagents and introduce them into an oligomer synthesis scheme. The process is certainly not limited to nucleotides alone. Aptamer Medicinal Chemistry schemes may include substituents that introduce steric bulk, hydrophobicity, hydrophilicity, lipophilicity, 115 WO 2007/035922 PCT/US2006/037276 lipophobicity, positive charge, negative charge, neutral charge, zwitterions, polarizability, nuclease-resistance, conformational rigidity, conformational flexibility, protein-binding characteristics, mass etc. Aptamer Medicinal Chemistry schemes may include base modifications, sugar-modifications or phosphodiester linkage-modifications. [00347] When considering the kinds of substituents that are likely to be beneficial within the context of a therapeutic aptamer, it may be desirable to introduce substitutions that fall into one or more of the following categories: (1) Substituents already present in the body, e.g., 2'-deoxy, 2'-ribo, 2'-O-methyl purines or pyrimidines or 5-methyl cytosine. (2) Substituents already part of an approved therapeutic, e.g., phosphorothioate-linked oligonucleotides. (3) Substituents that hydrolyze or degrade to one of the above two categories, e.g., methylphosphonate-linked oligonucleotides. Example 2B.1: Optimization of ARC979 by Phosphorothioate substitution. [00348] ARC979 (SEQ ID NO 177) is a 34 nucleotide aptamer to IL-23 of dRmY composition. 21 phosphorothioate derivatives of ARC979 were designed and synthesized in which single phosphorothioate substitutions were made at each phosphate linkage (ARC 1149 to ARC 1169) (SEQ ID NO 203 to SEQ ID NO 223) (see Table 27). These molecules were gel purified and assayed for IL-23 binding using the dot blot assay as described above and compared to each other and to the parent molecule, ARC979. An 8 point IL-23 titration (0 nM to 300 nM, 3 fold serial dilutions) was used in the binding assay. Calculated KDs are summarized in Table 28. [00349] The inclusion of phosphorothioate linkages in ARC979 was well tolerated when compared to ARC979. Many of these constructs have an increased proportion binding to IL-23 and additionally have improved (i.e., lower) KD values (Figure 15). A similar increase in affinity is seen in competition assays (Figure 16), which further supports that the phosphorothioate derivatives of ARC979 compete for IL-23 at a higher affinity than ARC979. [00350] Unless noted otherwise, each of the sequences listed in Table 27 below are in the 5'-3' direction, may be derivatized with polyalkylene glycol ("PAG") moieties, and may or may not contain capping (e.g., a 3'-inverted dT). 116 WO 2007/035922 PCT/US2006/037276 [00351] Table 27: Sequences of ARC979 phosphorothioate derivatives: Single Phosphorothioate substitutions SEQ Phosphorothiote ID linker between NO ARC# bases (xy) Sequence 203 ARC1149 1 2 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 204 ARC1150 2 3 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 205 ARC1151 6 7 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 206 ARC1152 7 8 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 207 ARC1153 8 9 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 208 ARC1154 9 10 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 209 ARC1155 10 11 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 210 ARC1156 11 12 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 211 ARC1157 12 13 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 212 ARC1158 13 14 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 213 ARC1159 14 15 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 214 ARC1160 18 19 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 215 ARC1161 19 20 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 216 ARC1162 20 21 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 217 ARC1163 21 22 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 218 ARC1164 22 23 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 219 ARC1165 26 27 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 220 ARC1166 27 28 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 221 ARC1167 28 29 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 222 ARC1168 32 33 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU 223 ARC1169 33 34 ACAGGCAAGUAAUUGGGGAGUGCGGGCGGGGUGU [00352] Table 28: KD summary for ARC979 phopsphorothioate derivatives SEQ KD KD ID (+tRNA) KD (-tRNA) (competition) NO ARC# nM nM uM 177 ARC979 93 90 9 203 ARC1149 not tested 204 ARC1150 not tested 205 ARC1151 142 117 WO 2007/035922 PCT/US2006/037276 206 ARC1152 232 207 ARC1153 174 208 ARC1154 412 209 ARC1155 168 210 ARC1156 369 211 ARC1157 69 212 ARC1158 192 213 ARC1159 77 214 ARC1160 38 5 215 ARC1161 55 6 216 ARC1162 47 6 217 ARC1163 49 8 218 ARC1164 79 219 ARC1165 55 220 ARC1166 132 221 ARC1167 107 222 ARC1168 82 223 ARC1169 74 Example 2B.2: Optimization: 2'-OMe, phosphorothioate and Inosine substitutions [003531 Systematic modifications were made to ARC979 (SEQ ID NO 177) to increase overall stability and plasma nuclease resistance. The most stable and potent variant of ARC979 was identified through a systematic synthetic approach involving 4 phases of aptamer synthesis, purification and assay for binding activity. The first step in the process was the synthesis and assay for binding activity of ARC1386 (SEQ ID NO 224) (ARC979 with a 3'-inverted-dT). Once ARC1386 (SEQ ID NO 224) was shown to bind to IL-23 with an affinity similar to that of the parent molecule ARC979 (SEQ ID NO 177), all subsequent derivatives of ARC979 were synthesized with a stabilizing 3'-inverted-dT. [00354] The dot blot binding assay previously described was used to characterize the relative potency of the majority of the aptamers synthesized. For KD determination, chemically synthesized aptamers were purified using denaturing polyacrylamide gel electrophoresis, 5'end labeled with y- 32 P ATP and were tested for direct binding to full 118 WO 2007/035922 PCT/US2006/037276 human IL-23. An 8 point protein titration was used in the dot blot binding assay (either {100 nM, 30 nM, 10 nM, 3 nM, 1 nM, 300 pM, 100 pM, 0 pM} or {10 nM, 3 nM, 1 nM, 300 pM, 100 pM, 30 pM, 10 pM, 0 pM}) in Dulbecco's PBS (with Mg "and Ca *) with 0.1 mg/ mL BSA. KD values were calculated by fitting the equation y= (max/(l+K/protein))+yint using KaleidaGraph (KaleidaGraph v. 3.51, Synergy Software). Sequences of the ARC979 derivatives synthesized, purified and assayed for binding to IL 23 as well as the results of the protein binding characterization are tabulated below in Tables 29 and 30. As can be seen in Table 30, and as previously described in Example 2A.3 above, ARC1386 (SEQ ID NO 224) (which is ARC979 (SEQ ID NO 177) with a 3' inverted dT) has a KD of 1 nM under these conditions. [00355] In phase 1 of the optimization process, comprised of ARC1427-ARC1471 (SEQ ID NOs 225-269), each individual purine residue in ARC 1386 (SEQ ID NO 224) was replaced by the corresponding 2'-O methyl containing residue. Additionally in phase 1, a series of individual and composite phosphorothioate substitutions were tested based on results generated previously which had suggested that in addition to conferring nuclease stability, phosphorothioate substitutions enhanced the binding affinity of derivatives of ARC979. Finally at the end of phase 1, a series of aptamers were tested that explored further the role of stem 1 in the functional context of ARC979/ARC 1386. As seen from the binding data in Table 30, many positions readily tolerated substitution of a deoxy residue for a 2'-O methyl residue. Addition of any particular phosphorothioate did not appear to confer a significant enhancement in the affinity of the aptamers. Interestingly, as can be seen by comparison of ARC1465-1471 (SEQ ID NOs 263-269), stem 1 was important for maintenance of high affinity binding, however its role appeared to be a structural clamp since introduction of PEG spacers between the aptamer core and the 2 strands that comprise stem 1 did not appear to significantly impact the binding properties of the aptamers. [00356] Based upon the structure activity relationship (SAR) results of the from phase 1 of the optimization process, a second series of aptamers were designed, synthesized, purified and tested for binding to IL-23. In phase 2 optimization, comprised of ARC1539 ARC1545 (SEQ ID NOs 270-276), the data from phase 1 was used to generate more highly modified composite molecules using exclusively 2'-O methyl substitutions. For these and all subsequent molecules, the goal was to identify molecules that retained an affinity (KD) of ~ 2 nM or better as well as an extent of binding at 100 nM (or 10 nM in phases 3 and 4) IL 119 WO 2007/035922 PCT/US2006/037276 23 of at least 50%. The best of these in terms of simple binding affinity was ARC1544 (SEQ ID NO 275). [003571 In phase 3 of optimization, comprised of ARC1591-ARC1626 (SEQ ID NOs 277-312), the stability of the G-quartet structure of ARC979 (SEQ ID NO 177) was probed by assaying for IL-23 binding during systematic replacement of (deoxy guanosine) dG with deoxy inosine (dI). Since deoxy inosine lacks the exocyclic amine found in deoxy guanosine, a single amino to N7 hydrogen bond is removed from a potential G-quartet for each dG to dI substitution. As seen from the data, only significant substitutions lead to substantial decreases in affinity for IL-23 suggesting that the aptamer structure is robust. Additionally, the addition of phosphorothioate containing residues into the ARC 1544 (SEQ ID NO 275) context was evaluated (comprising ARC 1620 to ARC 1626 (SEQ ID NOs 306 312). As can be seen in Table 30 the affinities of ARC1620-1626 (SEQ ID NOs 306-312) were in fact improved relative to ARC979 (SEQ ID NO 177). Figure 17 depicts the binding curves for select ARC979 derivatives (ARC 1624 and ARC 1625) from the phase 3 optimization efforts, showing the remarkably improved binding affinities conferred by the inclusion of select phosphorothioate containing residues, compared to the parent molecule ARC979. [003581 Phase 4 of optimization, comprised of ARC1755-1756 (SEQ ID NOs 313-314), involved only 2 sequences in an attempt to introduce more deoxy to 2'-O methyl substitutions and retain affinity. As can be seen with ARC1755 and 1756, these experiments were successful. [00359] Unless noted otherwise, each of the sequences listed in Table 29 are in the 5' to 3' direction and may be derivatized with polyalkylene glycol ("PAG") moieties. [00360] Table 29: Sequence information Phase 1-4 ARC979 optimization SEQ ARC # Description Sequence (5' -> 3'), (3T = inv dT), (T=dT), ID NO (s=phosphorothioate), (mN = 2'-O Methyl containing residue) (dl = deoxy inosine containing residue) 224 ARC 13 ARC 979 with dAmCdAdGdGmCdAdAdGmUdAdAmUmUdGd 86 3'-inv dT GdGdGdAdGmUdGmCdGdGdGmCdGdGdGdG mUdGmU-3T 225 ARC14 ARC979 opt nAmCdAdGdGmCdAdAdGmUdAdAmUmUdG 27 phase 1 dGdGdGdAdGmUdGmCdGdGdGmCdGdGdGd GmUdGmU-3T 120 WO 2007/035922 PCT/US2006/037276 226 ARC14 ARC979 opt dAnCmAdGdGnCdAdAdGmUdAdAmUnUdG 28 phase 1 dGdGdGdAdGnUdGmCdGdGdGmCdGdGdGd GmUdGmU-3T 227 ARC14 ARC979 opt dAnCdAnGdGnCdAdAdGmUdAdAnUmUdG 29 phase 1 dGdGdGdAdGnUdGnCdGdGdGmCdGdGdGd GnUdGmU-3T 228 ARC14 ARC979 opt dAmCdAdGmGnCdAdAdGmUdAdAmUnUdG 30 phase 1 dGdGdGdAdGnUdGnCdGdGdGmCdGdGdGd GmUdGmU-3T 229 ARC14 ARC979 opt dAnCdAdGdGmCmAdAdGnUdAdAnUnUdG 31 phase 1 dGdGdGdAdGmUdGmCdGdGdGmCdGdGdGd GmUdGmU-3T 230 ARC14 ARC979 opt dAnCdAdGdGmCdAmAdGmUdAdAnUmUdG 32 phase 1 dGdGdGdAdGnUdGnCdGdGdGmCdGdGdGd GmUdGmuU-3T 231 ARC14 ARC979 opt dAmnCdAdGdGmCdAdAnGmUdAdAnUnUdG 33 phase 1 dGdGdGdAdGmUdGmCdGdGdGmCdGdGdGd GmUdGmU-3T 232 ARC14 ARC979 opt dAnCdAdGdGmCdAdAdGmUnAdAnUnUdG 34 phase 1 dGdGdGdAdGnUdGmCdGdGdGmCdGdGdGd GmUdGmU-3T 233 ARC14 ARC979 opt dAnCdAdGdGmCdAdAdGmUdAmAmUmUdG 35 phase 1 dGdGdGdAdGnUdGmCdGdGdGmCdGdGdGd GnUdGnU-3T 234 ARC14 ARC979 opt dAmCdAdGdGmCdAdAdGmUdAdAnUnUmG 36 phase 1 dGdGdGdAdGmUdGmCdGdGdGmCdGdGdGd GnUdGnU-3T 235 ARC14 ARC979 opt dAnCdAdGdGmCdAdAdGmUdAdAnUmUdG 37 phase 1 mGdGdGdAdGnUdGmCdGdGdGmCdGdGdGd GmUdGmU-3T 236 ARC14 ARC979 opt dAmCdAdGdGnCdAdAdGnUdAdAmUmUdGd 38 phase 1 GmGdGdAdGmUdGmCdGdGdGnCdGdGdGdG mnUdGmU-3T 237 ARC14 ARC979 opt dAmCdAdGdGnCdAdAdGmUdAdAnUmUdGd 39 phase 1 GdGmGdAdGmUdGmCdGdGdGmCdGdGdGdG nUdGmU-3T 238 ARC14 ARC979 opt dAmCdAdGdGmCdAdAdGmUdAdAnUmUdGd 40 phase 1 GdGdGnAdGnUdGmCdGdGdGmCdGdGdGdG mUdGmU-3T 239 ARC14 ARC979 opt dAmCdAdGdGmCdAdAdGmUdAdAnUnUdGd 41 phase 1 GdGdGdAmGnUdGmCdGdGdGmCdGdGdGdG mUdGnU-3T 121 WO 2007/035922 PCT/US2006/037276 240 ARC14 ARC979 opt dAn1CdAdGdGmCdAdAdGmUdAdAmUmUdGd 42 phase 1 GdGdGdAdGnUmGnCdGdGdGmCdGdGdGdG nUdGmU-3T 241 ARC 14 ARC979 opt dAmCdAdGdGnCdAdAdGmUdAdAmUmUdGd 43 phase 1 GdGdGdAdGmUdGmCmGdGdGnCdGdGdGdG mUdGmU-3T 242 ARC 14 ARC979 opt dAmCdAdGdGmCdAdAdGnUdAdAnUnUdGd 44 phase 1 GdGdGdAdGnUdGnCdGmGdGmCdGdGdGdG nUdGmU-3T 243 ARC 14 ARC979 opt dAmCdAdGdGnCdAdAdGmUdAdAmUmUdGd 45 phase 1 GdGdGdAdGnUdGmCdGdGmGmCdGdGdGdG mUdGmU-3T 244 ARC 14 ARC979 opt dAnCdAdGdGnCdAdAdGmUdAdAmUmUdGd 46 phase 1 GdGdGdAdGnUdGmCdGdGdGnCmGdGdGdG nUdGmU-3T 245 ARC14 ARC979 opt dAnCdAdGdGmCdAdAdGmUdAdAnUmUdGd 47 phase 1 GdGdGdAdGmUdGmCdGdGdGnCdGmGdGdG mUdGmU-3T 246 ARC14 ARC979 opt dAmCdAdGdGmCdAdAdGmUdAdAmUnUdGd 48 phase 1 GdGdGdAdGmIUdGmCdGdGdGmCdGdGmGdG mUdGmU-3T 247 ARC14 ARC979 opt dAmCdAdGdGmCdAdAdGnUdAdAmUmUdGd 49 phase 1 GdGdGdAdGnUdGmCdGdGdGmCdGdGdGmG mUdGmU-3T 248 ARC14 ARC979 opt dAmCdAdGdGmCdAdAdGmUdAdAnUmUdGd 50 phase 1 GdGdGdAdGmUdGmCdGdGdGmCdGdGdGdG mUmGmU-3T 249 ARC14 ARC979 opt mAmCmAdGdGmCdAdAdGnUdAdAmUnUdG 51 phase 1 dGdGdGdAdGmUdGmCdGdGdGmCdGdGdGd GmUmGmU-3T 250 ARC14 ARC979 opt dAnCdAdGdGmCniAmAdGnUdAdAmUmUn 52 phase 1 GdGdGdGdAdGmUdGmCdGdGdGmCdGdGdG dGmUdGnU-3T 251 ARC14 ARC979 opt dAmCdA-s 53 phase 1 dGdGmCdAdAdGnUdAdAnUmUdGdGdGdGd AdGmUdGmCdGdGdGmCdGdGdGdGmUdGm U-3T 252 ARC14 ARC979 opt dAnCdAdG-s 54 phase 1 dGmCdAdAdGnUdAdAnUmUdGdGdGdGdAd GmUdGnCdGdGdGmCdGdGdGdGmUdGmU 3T 253 ARC14 ARC979 opt dAmCdAdGdG-s 55 phase 1 mCdAdAdGmUdAdAnUnUdGdGdGdGdAdGm 122 WO 2007/035922 PCT/US2006/037276 UdGmCdGdGdGmCdGdGdGdGnUdGmU-3T 254 ARC14 ARC979 opt dAnCdAdGdGnCdAdAdGmUdAdAmUmUdG 56 phase 1 s dGdGdGdAdGinUdGmCdGdGdGmCdGdGdGd GmUdGmU-3T 255 ARC14 ARC979 opt dAnCdAdGdGmCdAdAdGmUdAdAmUmUdGd 57 phase 1 G-s dGdGdAdGmUdGmCdGdGdGmCdGdGdGdGm UdGmU-3T 256 ARC14 ARC979 opt dAnCdAdGdGmCdAdAdGmUdAdAmUmUdGd 58 phase 1 GdG-s dGdAdGnUdGmCdGdGdGmCdGdGdGdGmUd GmU-3T 257 ARC14 ARC979 opt dAmCdAdGdGmCdAdAdGmUdAdAmUmUdGd 59 phase 1 GdGdGdAdGmUdGmC-s dGdGdGmCdGdGdGdGmUdGmU-3T 258 ARC14 ARC979 opt dAmCdAdGdGmCdAdAdGmUdAdAmUmUdGd 60 phase 1 GdGdGdAdGmUdGmCdG-s dGdGnCdGdGdGdGnUdGmU-3T 259 ARC14 ARC979 opt dAnCdAdGdGmCdAdAdGnUdAdAnUnUdGd 61 phase 1 GdGdGdAdGnUdGnCdGdG-s dGmCdGdGdGdGmUdGmU-3T 260 ARC14 ARC979 opt dAnCdAdGdGmCdAdAdGmUdAdAmUmUdGd 62 phase 1 GdGdGdAdGnUdGmCdGdGdGmCdGdG-s dGdGmUdGmU-3T 261 ARC14 ARC979 opt dAnCdAdGdGnCdAdAdGmUdAdAmUmUdGd 63 phase 1 GdGdGdAdGniUdGnCdGdGdGmCdGdGdG-s dGmUdGmU-3T 262 ARC14 ARC979 opt dAnCdAdGdGmCdAdAdGnUdAdAmUmUdGd 64 phase 1 GdGdGdAdGnUdGmCdGdGdGmCdGdGdGdG s-nUdGmU-3T 263 ARC14 ARC979 opt dAmCdAdGdGmCdAdAdGnUdA-s 65 phase 1 dAnUmUdGdGdGdGdA-s-dG-s-nU-s-dG-s mCdGdGdG-s-mCdGdGdGdGnUdGnU-3T 264 ARC14 ARC979 opt dAnCdAPEGdGdGmCdAdAdGnUdAdAmUm 66 phase 1 UdGdGdGdGdAdGmUdGmCdGdGdGmCdGdG dGdGPEGnUdGmU-3T 265 ARC14 ARC979 opt mCmGmCdAPEGdGdGmCdAdAdGnUdAdAm 67 phase 1 UnUdGdGdGdGdAdGnUdGmCdGdGdGmCdG dGdGdGPEGmUdGmCmG-3T 266 ARC14 ARC979 opt dGdGmCdAdAdGmUdAdAmUnUdGdGdGdGd 68 phase 1 AdGmUdGnCdGdGdGmCdGdGdGdG-3T 123 WO 2007/035922 PCT/US2006/037276 267 ARC14 ARC979 opt dGdGmCmAmAdGmUdAdAmUmUnGdGdGdG 69 phase 1 dAdGnUdGmCdGdGdGmCdGdGdGdG-3T 268 ARC14 ARC979 opt dGdGmCdAdAdGmUdA-s 70 phase 1 dAnUnUdGdGdGdGdA-s-dG-s-nU-s-dG-s mCdGdGdG-s-mCdGdGdGdG-3T 269 ARC14 ARC979 opt dGdGmCmAmAdGmUdA-s 71 phase 1 dAnUmUnGdGdGdGdA-s-dG-s-nU-s-dG-s mCdGdGdG-s-mCdGdGdGdG-3T 270 ARC15 ARC979 opt mAmCdAdGdGnCdAdAdGmUdAdAnUmUdG 39 phase 2 dGdGdGdAdGmUdGmCdGdGdGmCdGdGdGd GmUmGmU-3T 271 ARC15 ARC979 opt dArnCdAdGdGmCdAmnAmGmUnAdAnUmUd 40 phase 2 GdGdGdGdAdGmUdGmCdGdGdGnCdGdGdG dGmUdGmU-3T 272 ARC15 ARC979 opt dAmCdAdGdGmCdAdAdGmUdAdAmUmUdGd 41 phase 2 GdGmGnAmGmUmGnCdGdGdGmCdGdGdGd GmUdGmU-3T 273 ARC15 ARC979 opt dAmCdAdGdGnCdAdAdGmUdAdAmUmUdGd 42 phase 2 GdGdGdAdGmUdGmCdGdGnGmCmGmGdGd GnUdGmU-3T 274 ARC15 ARC979 opt mAmCdAdGdGmCdAmAmGmUmAdAmUmUd 43 phase 2 GdGdGmGnAmGmUmGmCdGdGmGmCmGm GdGdGmUmGmU-3T 275 ARC15 ARC979 opt dAnCdAdGdGmCdAdAdGmUdAdAmUmUdG 44 phase 2 mGmGdGdAdGmUdGnCmGmGdGmCdGdGn GmGmUdGnU-3T 276 ARC15 ARC979 opt nAmCdAdGdGmCdAmAmGmUmAdAmUmUd 45 phase 2 GmGnGmGmAmGmUmGmCmGmGmGnCmG mGmGmGmUnGmU-3T 277 ARC15 ARC979 opt dAmCdAdIdGmCdAdAdGnUdAdAnUnUdGd 91 phase 3 GdGdGdAdGnUdGmCdGdGdGmCdGdGdGdG mUdGmU-3T 278 ARC15 ARC979 opt dAnCdAdGdlmCdAdAdGmUdAdAmUmUdGd 92 phase 3 GdGdGdAdGmUdGmCdGdGdGmCdGdGdGdG mUdGnU-3T 279 ARC15 ARC979 opt dAnCdAdIdImCdAdAdGmUdAdAnUnUdGdG 93 phase 3 dGdGdAdGmUdGmCdGdGdGmCdGdGdGdGm UdGmU-3T 280 ARC15 ARC979 opt dAmCdAdGdGmCdAdAdImUdAdAnUmUdGd 94 phase 3 GdGdGdAdGmUdGinCdGdGdGmCdGdGdGdG mUdGmU-3T 124 WO 2007/035922 PCT/US2006/037276 281 ARC15 ARC979 opt dAmCdAdGdGmCdAdAdGmUdAdAmUnUdld 95 phase 3 GdGdGdAdGnUdGmCdGdGdGmCdGdGdGdG mUdGmU-3T 282 ARC15 ARC979 opt dAnCdAdGdGmCdAdAdGmUdAdAmUmUdGd 96 phase 3 IdGdGdAdGmUdGmCdGdGdGmCdGdGdGdGm UdGmU-3T 283 ARC15 ARC979 opt dAmCdAdGdGmCdAdAdGmUdAdAmUmUdGd 97 phase 3 GdIdGdAdGmUdGmCdGdGdGmCdGdGdGdGm UdGmU-3T 284 ARC15 ARC979 opt dAmCdAdGdGmCdAdAdGnUdAdAmUmUdGd 98 phase 3 GdGdldAdGmUdGmCdGdGdGmCdGdGdGdGm UdGnU-3T 285 ARC15 ARC979 opt dAmCdAdGdGmCdAdAdGnUdAdAmUnUdIdI 99 phase 3 dGdGdAdGmUdGmCdGdGdGmCdGdGdGdGm UdGmU-3T 286 ARC16 ARC979 opt dAnCdAdGdGmCdAdAdGmUdAdAmUmUdGd 00 phase 3 IdIdGdAdGnUdGmCdGdGdGnCdGdGdGdGm UdGmU-3T 287 ARC16 ARC979 opt dAmCdAdGdGmCdAdAdGmUdAdAmUmUdGd 01 phase 3 GdIdIdAdGmUdGmCdGdGdGmCdGdGdGdGm UdGmU-3T 288 ARC16 ARC979 opt dAmCdAdGdGmCdAdAdGmUdAdAmUnUdIdI 02 phase 3 dIdIdAdGmnUdGmCdGdGdGmCdGdGdGdGnU dGmU-3T 289 ARC16 ARC979 opt dAmCdAdGdGnCdAdAdGnUdAdAinUmUdGd 03 phase 3 GdGdGdAdImUdGnCdGdGdGmCdGdGdGdGm UdGmU-3T 290 ARC16 ARC979 opt dAmCdAdGdGmCdAdAdGmUdAdAnUmUdGd 04 phase 3 GdGdGdAdGmUdImCdGdGdGmCdGdGdGdGm UdGnU-3T 291 ARC16 ARC979 opt dAmCdAdGdGmCdAdAdGnUdAdAnUnUdGd 05 phase 3 GdGdGdAdGmUdGmCdIdGdGmCdGdGdGdGm UdGmU-3T 292 ARC16 ARC979 opt dAmCdAdGdGmCdAdAdGmUdAdAmUmUdGd 06 phase 3 GdGdGdAdGmUdGmCdGdIdGmCdGdGdGdGm UdGnU-3T 293 ARC16 ARC979 opt dAmCdAdGdGnCdAdAdGnUdAdAnUmUdGd 07 phase 3 GdGdGdAdGmUdGmCdGdGdlmCdGdGdGdGm UdGmU-3T 294 ARC16 ARC979 opt dAnCdAdGdGnCdAdAdGnUdAdAnUmUdGd 08 phase 3 GdGdGdAdGnUdGmCdIdIdGmCdGdGdGdGm UdGmU-3T 125 WO 2007/035922 PCT/US2006/037276 295 ARC16 ARC979 opt dAnCdAdGdGmCdAdAdGmUdAdAmUmUdGd 09 phase 3 GdGdGdAdGnUdGmCdGdIdImCdGdGdGdGn UdGmU-3T 296 ARC16 ARC979 opt dAnCdAdGdGmCdAdAdGmUdAdAmUnUdGd 10 phase 3 GdGdGdAdGnUdGnCdldldnCdGdGdGdGnU dGmU-3T 297 ARC16 ARC979 opt dAnCdAdGdGmCdAdAdGmUdAdAmUmUdGd 11 phase 3 GdGdGdAdGmUdGmCdGdGdGmCdIdGdGdGm UdGmU-3T 298 ARC16 ARC979 opt dAmCdAdGdGmCdAdAdGnUdAdAnUmUdGd 12 phase 3 GdGdGdAdGnUdGmCdGdGdGmCdGdIdGdGm UdGmU-3T 299 ARC16 ARC979 opt dAmnCdAdGdGnCdAdAdGmUdAdAmUmUdGd 13 phase 3 GdGdGdAdGmUdGmCdGdGdGmCdGdGdldGm UdGmU-3T 300 ARC16 ARC979 opt dAnCdAdGdGnCdAdAdGmUdAdAmUmUdGd 14 phase 3 GdGdGdAdGmUdGmCdGdGdGmCdGdGdGdIm UdGmU-3T 301 ARC16 ARC979 opt dAmCdAdGdGmCdAdAdGmUdAdAmUmUdGd 15 phase 3 GdGdGdAdGmUdGmCdGdGdGmCdIdIdGdGm UdGmU-3T 302 ARC16 ARC979 opt dAmCdAdGdGnCdAdAdGmUdAdAmUnUdGd 16 phase 3 GdGdGdAdGmUdGmCdGdGdGmCdGdIdIdGm UdGinU-3T 303 ARC16 ARC979 opt dAmCdAdGdGnCdAdAdGmUdAdAnUmUdGd 17 phase 3 GdGdGdAdGmUdGmCdGdGdGmCdGdGdIdIm UdGmU-3T 304 ARC16 ARC979 opt dAmCdAdGdGmCdAdAdGimUdAdAnUmUdGd 18 phase 3 GdGdGdAdGnUdGmnCdGdGdGmCdIdIdIdImUd GnU-3T 305 ARC16 ARC979 opt dAnCdAdGdGmCdAdAdGnUdAdAmUnUdGd 19 phase 3 GdGdGdAdGnUdGmCdGdGdGmCdGdGdGdG mUdImU-3T 306 ARC16 ARC979 opt dAmC-s 20 phase 3 dAdGdGmCdAdAdGmUdAdAnUmUdGmGmG dGdAdGnUdGnCmGmGdGmCdGdGmGmGm UdGnU-3T 307 ARC16 ARC979 opt dlAmCdA-s-dG-s 21 phase 3 dGmCdAdAdGmUdAdAnUnUdGmGnGdGdA dGnUdGnCmGmGdGmCdGdGmGmGnUdGm U-3T 126 WO 2007/035922 PCT/US2006/037276 308 ARC16 ARC979 opt dAmCdAdGdGmC-s-dA-s-dA-s-dGmU-s-dA-s 22 phase 3 dAmUmU-s dGnGmnGdGdAdGmUdGmCmGmGdGmCdGdG mGmGnUdGmU-3T 309 ARC16 ARC979 opt dAmCdAdGdGnCdAdAdGmUdAdAnUnUdG 23 phase 3 mGmG-s-dG-s-dA-s-dGmU-s dGmCmGmGdGmCdGdGnGmGmUdGmU-3T 310 ARC16 ARC979 opt dAmCdAdGdGnCdAdAdGnUdAdAmUnUidG 24 phase 3 mGmGdGdAdGmUdGmCmGnG-s-dGmC-s-dG s-dGmGmGnUdGmU-3T 311 ARC16 ARC979 opt dAmCdAdGdGnCdAdAdGmUdAdAmUmUdG 25 phase 3 mGmGdGdAdGnUdGnCmGmGdGmCdGdGm GmGmU-s-dGmU-3T 312 ARC16 ARC979 opt dAmC-s-dA-s-dG-s-dGmC-s-dA-s-dA-s-dGnU 26 phase 3 s-dA-s-dAmUnU-s-dGmGmG-s-dG-s-dA-s dGnU-s-dGmCmGmG-s-dGmC-s-dG-s dGnGmGmU-s-dGmU-3T 313 ARC17 ARC979 opt mAmC-s-dAdGdGmC-s-dAnAmGmUimA-s 55 phase 4 dAmUmU-s dGmGmGmGmAmGnUnGnCmGnGmGmCm GmGnGrnGmUmGmU-3T 314 ARC17 ARC979 opt mAmC-s-dAdGdGmC-s-dAmAmGnUmA-s 56 phase 4 dAnUnU-s-dGmGmG-s-dG-s-dA-s-dGnU-s dGmCmGmGmGnCmGnGmGmGmUmGnU 3T [003611 Table 30: Binding Characterization SEQ ID NO % binding at 100 nM (through ARC # Description KD (nM) ARC1619) or at 10 nM (ARC1620 1756) 224 ARC 979 ARC1386 with 3'-inv 1 69.9 dT 225 ARC1427 ARC979 opt phase 1 3.0 49.4 226 ARC1428 ARC979 opt phase 1 1.8 57.8 127 WO 2007/035922 PCT/US2006/037276 227 ARC1429 ARC979 opt phase 1 29.5 48.4 228 ARC1430 ARC979 opt phase 1 14.2 51.6 229 ARC1431 ARC979 opt phase 1 10.0 56.3 230 ARC1432 ARC979 opt phase 1 3.8 57.9 231 ARC1433 ARC979 opt phase 1 2.8 55.2 232 ARC1434 ARC979 opt phase 1 3.0 52.9 233 ARC1435 ARC979 opt phase 1 9.8 51.2 234 ARC1436 ARC979 opt phase 1 15.1 46.9 235 ARC1437 ARC979 opt phase 1 3.9 43.1 236 ARC1438 ARC979 opt phase 1 6.0 36.7 237 ARC1439 ARC979 opt phase 1 4.8 43.5 238 ARC1440 ARC979 opt phase 1 6.7 54.9 239 ARC1441 ARC979 opt phase 1 2.7 49.8 240 ARC1442 ARC979 opt phase 1 2.8 60.5 241 ARC1443 ARC979 opt phase 1 2.0 52.8 242 ARC1444 ARC979 opt phase 1 4.4 58.1 243 ARC1445 ARC979 opt phase 1 2.8 56.3 244 ARC1446 ARC979 opt phase 1 2.1 55.0 245 ARC1447 ARC979 opt phase 1 2.5 56.5 246 ARC1448 ARC979 opt phase 1 2.3 59.5 128 WO 2007/035922 PCT/US2006/037276 247 ARC1449 ARC979 opt phase 1 2.6 48.4 248 ARC1450 ARC979 opt phase 1 2.6 46.5 249 ARC1451 ARC979 opt phase 1 10.2 46.1 250 ARC1452 ARC979 opt phase 1 18.9 56.9 251 ARC1453 ARC979 opt phase 1 4.4 65.0 252 ARC1454 ARC979 opt phase 1 2.7 61.6 253 ARC1455 ARC979 opt phase 1 1.6 56.6 254 ARC1456 ARC979 opt phase 1 3.2 55.5 255 ARC1457 ARC979 opt phase 1 3.0 56.1 256 ARC1458 ARC979 opt phase 1 2.9 49.6 257 ARC1459 ARC979 opt phase 1 4.0 50.7 258 ARC1460 ARC979 opt phase 1 5.8 46.1 259 ARC1461 ARC979 opt phase 1 3.7 47.3 260 ARC1462 ARC979 opt phase 1 1.7 53.4 261 ARC1463 ARC979 opt phase 1 3.6 53.5 262 ARC1464 ARC979 opt phase 1 2.4 54.6 263 ARC1465 ARC979 opt phase 1 1.3 57.0 264 ARC1466 ARC979 opt phase 1 1.9 38.7 265 ARC1467 ARC979 opt phase 1 1.7 57.0 266 ARC1468 ARC979 opt phase 1 10.0 49.8 129 WO 2007/035922 PCT/US2006/037276 267 ARC1469 ARC979 opt phase 1 49.8 59.8 268 ARC1470 ARC979 opt phase 1 8.6 61.0 269 ARC1471 ARC979 opt phase 1 23.5 62.9 270 ARC1539 ARC979 opt phase 2 6.6 43.8 271 ARC1540 ARC979 opt phase 2 7.5 50.3 272 ARC1541 ARC979 opt phase 2 3.9 57.0 273 ARC1542 ARC979 opt phase 2 1.2 57.6 274 ARC1543 ARC979 opt phase 2 5.9 40.9 275 ARC1544 ARC979 opt phase 2 0.9 58.6 276 0.4 & 62.0 ARC1545 ARC979 opt (the binding phase 2 curve was strongly biphasic) 17.4 & 20.9 277 ARC1591 ARC979 opt phase 3 54.8 278 ARC1592 ARC979 opt phase 3 8.1 54.4 279 ARC1593 ARC979 opt phase 3 13.8 51.0 280 ARC1594 ARC979 opt phase 3 4.2 60.1 281 ARC1595 ARC979 opt phase 3 5.4 53.9 282 ARC1596 ARC979 opt phase 3 11.1 59.0 283 ARC1597 ARC979 opt phase 3 11.2 61.3 284 ARC1598 ARC979 opt phase 3 4.7 61.0 130 WO 2007/035922 PCT/US2006/037276 285 ARC1599 ARC979 opt phase 3 7.2 57.7 286 ARC1600 ARC979 opt phase 3 15.6 61.3 287 ARC1601 ARC979 opt phase 3 4.4 58.6 288 ARC1602 ARC979 opt phase 3 40.8 64.4 289 ARC1603 ARC979 opt phase 3 1.6 64.2 290 ARC1604 ARC979 opt phase 3 2.1 50.2 291 ARC1605 ARC979 opt phase 3 7.5 56.8 292 ARC1606 ARC979 opt phase 3 5.0 60.3 293 ARC1607 ARC979 opt phase 3 3.3 61.5 294 ARC1608 ARC979 opt phase 3 9.7 61.1 295 ARC1609 ARC979 opt phase 3 4.7 60.5 296 ARC1610 ARC979 opt phase 3 5.2 60.4 297 ARC1611 ARC979 opt phase 3 1.7 62.1 298 ARC1612 ARC979 opt phase 3 1.9 60.9 299 ARC1613 ARC979 opt phase 3 2.3 58.4 300 ARC1614 ARC979 opt phase 3 1.7 60.5 301 ARC1615 ARC979 opt phase 3 5.8 55.2 302 ARC1616 ARC979 opt phase 3 6.1 59.5 303 ARC1617 ARC979 opt phase 3 4.1 61.9 304 ARC1618 ARC979 opt phase 3 34.0 67.0 131 WO 2007/035922 PCT/US2006/037276 305 ARC1619 ARC979 opt phase 3 2.8 52.1 306 ARC1620 ARC979 opt phase 3 0.4 68.0 307 ARC1621 ARC979 opt phase 3 0.5 64.6 308 ARC1622 ARC979 opt phase 3 0.3 66.0 309 ARC1623 ARC979 opt phase 3 0.2 68.7 310 ARC1624 ARC979 opt phase 3 0.4 68.0 311 ARC1625 ARC979 opt phase 3 0.4 75.0 312 ARC1626 ARC979 opt phase 3 0.1 79.2 313 ARC1755 ARC979 opt phase 4 0.8 31 314 ARC1756 ARC979 opt phase 4 0.5 56 *30min RT incubation for KD determination * X Dulbecco's PBS (with Ca+* and Mg**) +0. 1mg/mL BSA reaction buffer EXAMPLE 2C: Plasma stability of anti-IL-23 aptamers [00362] A subset of the aptamers identified during the optimization process was assayed for nuclease stability in human plasma. Plasma nuclease degradation was measured using denaturing polyacrylamide gel electrophoresis as described below. Briefly, for plasma stability determination, chemically synthesized aptamers were purified using denaturing polyacrylamide gel electrophoresis, 5'end labeled with y- 32 P ATP and then gel purified again. Trace 32 P labeled aptamner was incubated in the presence of 100 nM unlabeled aptamer in 95% human plasma in a 200 microliter binding reaction. The reaction for the time zero point was made separately with the same components except that the plasma was replaced with PBS to ensure that the amount of radioactivity loaded on gels was consistent across the experiment. Reactions were incubated at 37 'C in a theriocycler for the 1, 3, 10, 30 and 100 hours. At each time point, 20 microliters of the reaction was removed, combined with 200 microliters of fonnamide loading dye and flash frozen in liquid nitrogen and 132 WO 2007/035922 PCT/US2006/037276 stored at -20 'C. After the last time point was taken, frozen samples were thawed and 20 microliters was removed from each time point. SDS was then added to the small samples to a final concentration of 0.1%. The samples were then incubated at 90 'C for 10 - 15 minutes and loaded directly onto a 15% denaturing PAGE gel and run at 12 W for 35 minutes. Radioactivity on the gels was quantified using a Storm 860 Phosphorimager system (Anersham Biosciences, Piscataway, NJ). The percentage of full length aptamer at each time point was determined by quantifying the full length aptamer band and dividing by the total counts in the lane. The fraction of full length aptamer at each time-point was then normalized to the percentage full length aptamer of the 0 hour time-point. The fraction of full length aptamer as a function of time was fit to the equation: ml *e^(-m2*m0) where ml is the maximum % full length aptamer (m1=100); and m2 is the rate of degradation. The half-life of the aptamer (T /2) is equal to the (ln 2) / m2. [00363] Sample data is shown in Figure 18 and the results for the aptamers tested are summarized in Table 31. Table 31: plasma stability SEQ ID NO ~T1/2 in ARC # Description human plasma (hrs) 177 ARC979 14 224 ARC 979 ARC1386 with 3'-inv 33 dT 307 ARC1621 ARC979 opt phase 3 59 308 ARC1622 ARC979 opt phase 3 54 309 ARC1623 ARC979 opt phase 3 45 310 ARC1624 ARC979 opt phase 3 35 311 ARC1625 ARC979 opt phase 3 31 133 WO 2007/035922 PCT/US2006/037276 312 ARC1626 ARC979 opt phase 3 113 313 ARC1755 ARC979 opt phase 4 83 314 ARC1756 ARC979 opt phase 4 96 EXAMPLE 2D: Synthesis of Aptamer-5'-PEG Conjugates 1003641 5'-PEG conjugates of the anti-IL-23 aptaners ARC1623 (SEQ ID NO 309) and ARC 1626 (SEQ ID NO 312) were prepared by first synthesizing 5'-amine modified versions of the aptamers to facilitate chemical coupling. 5' NH 2 dAmCdAdGdGmCdAdAdGmUdAdAmlUmUdGmGmG-s-dG-s-dA-s-dGmU-s dGmCmGmGdGmCdGdGmGmGmUdGmU-3T (ARC1987, SEQ ID NO 315) and 5' NH2 dAnC-s-dA-s-dG-s-dGmC-s-dA-s-dA-s-dGmU-s-dA-s-dAnUmU-s-dGmGmG-s-dG-s-dA s-dGmU-s-dGmCmGmG-s-dGmC-s-dG-s-dGmGmGmU-s-dGmU-3T (ARC1989, SEQ ID NO 316) were synthesized on an AKTA OligoPilot 100 synthesizer (GE Healthcare, Uppsala, Sweden) according to the recommended manufacturer's procedures using standard commercially available 2'-OMe RNA, DNA phosphoramidites (Glen Research, Sterling, VA) and an inverted deoxythymidine CPG support. Phosphorothioate linkages were introduced using a sulfurization reagent (Glen Research, Sterling, VA) according to standard procedures. Terminal amine functions were attached with a 5'-amino-modifier C6 TFA (Glen Research, Sterling, VA). After deprotection, the oligonucleotide was purified by ion exchange chromatography on Super Q 5PW (30) resin (Tosoh Biosciences) and ethanol precipitated. [003651 Aliquots of the 5'-amine-modified aptamers were conjugated to PEG moieties post-synthetically (e.g., 40 kDa PEG moieties). Aptamers were dissolved in a water/DMSO (1:1) solution to a concentration between 1.5 and 3 mM. Sodium carbonate buffer, pH 8.5, was added to a final concentration of 100 mM, and the oligo was reacted overnight with a 1.7- 3 fold molar excess of the desired PEG reagent (40 kDa Sunbright GL2-400NP p nitrophenyl carbonate ester [NOF Corp, Japan]) dissolved in an equal volume of acetonitrile. The resulting 40 kDa PEGylated products were purified by ion exchange chromatography on Super Q 5PW (30) resin (Tosoh Biosciences), and desalted using 134 WO 2007/035922 PCT/US2006/037276 reverse phase chromatography performed on Amberchrom CG300-S resin (Rohim and Haas), and lyophilized. [00366] A general schematic of the resulting 5'-PEGylated aptamer is shown in Figure 26. The resulting PEGylated aptamer sequences are listed below. Lower case letters "in", and "d" denote 2-0-methyl, and deoxy modifications respectively, "s" denotes an internucleotide phopshorothioate substitution, "NH" denotes an amine to facilitate chemical coupling, and "3T" denotes a 3' inverted dT. Binding analysis of ARC 1988 [003671 The Biacore biosensor system was used to measure the binding of ARC1988 (SEQ ID NO 317) to IL-23 compared to ARC1623 (SEQ ID NO 309). [003681 All biosensor binding measurements were performed at 25 0 C using a BIACORE 2000 equipped with a research-grade CM3 biosensor chip (BIACORE Inc. Piscataway, NJ). Purified recombinant human IL-23 (R&D Systems, Minnapolis, MN) was immobilized to the biosensor surface using amino-coupling chemistry. To achieve this, the surfaces of two flow cells were first activated for 7 minutes with a 1 : 1 mixture of 0.1 M NIS (Nhydroxysuccinimide) and 0.4 M EDC (3-(NNdimethylamine) propyl-N ethylcarbodiimide) at a flow rate of 5 pl/min. After surface activation, one flow cell was injected with 50 tg/ml of IL-23 at rate of 10 p1/minute for 15 minutes to allow for establishment of covalent bonds to the activated surface. Next, 1 M ethanolamine hydrochloride pH 8.5 was injected for 7min at rate of 5 tl/min to inactivate residual esters. As a negative control, a blank flow cell was prepared by injecting 1 M ethanolamine hydrochloride pH 8.5 continuously for 7 minutes to inactivate residual esters, without protein injection. [003691 For IL-23 binding, aptamers were serially diluted into HBS-P buffer (10mM HEPES pH7.4, 150mM NaCl, 0.005% Surfactant 20). Various concentrations of aptamer (ranging from 1.6 nM to 100 nM) samples were injected one at a time for binding at a rate of 20 p1/min continuously for 5 minutes followed by a period of no-injection for 5 minutes. To test subsequent concentrations, the surface was regenerated by injecting 1N NaCl for 30 seconds at a rate of 20 i1/min. Rate constant and dissociation constant were calculated using BlAevaluation software. The dissociation constants for both ARC 1988 (KD) were calculated to be ~ 2 nM, using the Biacore method, indicating that PEGylation had no effect on the binding affinity of ARC1988. 135 WO 2007/035922 PCT/US2006/037276 5' PEG conjugates of anti-IL-23 aptamers ARC1623 and ARC1626 ARC1988 (SEQ ID NO 317) (ARC1623 plus 40kDa PEG) PEG40K--nh-dAmCdAdGdGmCdAdAdGmUdAdAmUmUdGmGmG-s-dG-s-dA-s-dGmU-s dGmCnGnGdGmCdGdGmGmGnUdGnU-3T ARC 1990 (SEQ ID NO 318) (ARC1626 plus 40kDa PEG) PEG40K--nh-dAmC-s-dA-s-dG-s-dGmC-s-dA-s-dA-s-dGmU-s-dA-s-dAmUmU-s-dGmGmG-s-dG-s-dA-s dGmU-s-dGmCmGmG-s-dGmC-s-dG-s-dGmGmGmU-s-dGnU-3T Example 2E: Synthesis of Aptamer-3'-5'-PEG conjugates [003701 A 5'-3'-PEG conjugate of the anti-IL-23 aptamer ARC1623 (SEQ ID NO 309) was prepared by first synthesizing a 5'-amine modified version of the aptamer to facilitate chemical coupling. The oligonucleotide NH2 dAmCdAdGdGnCdAdAdGmUdAdAnUmUdGmGmG-s-dG-s-dA-s-dGmU-s dGmCmGnGdGmCdGdGmGmGmUdGmIU-NH2 (ARC2349, SEQ ID NO 319) was synthesized on an AKTA OligoPilot 100 synthesizer (GE Healthcare Uppsala, Sweden) according to the recommended manufacturer's procedures using standard commercially available 2'-OMe RNA, DNA phosphoramidites (Glen Research, Sterling, VA) and a 3' phthalimide-amino-modifier C6 CPG support (Glen Research, Sterling, VA). Tenninal amine functions were attached with a 5'-amino-modifier C6-TFA (Glen Research, Sterling, VA). Phosphorothioate linkages were introduced using a sulfurization reagent (Glen Research, Sterling, VA) according to standard procedures. After deprotection, the oligonucleotides was purified by ion exchange chromatography on Super Q 5PW (30) resin (Tosoh Biosciences) and ethanol precipitated. 1003711 Aliquots of the 3'-5'-diamine-modified aptamer were conjugated to PEG moieties post-synthetically (e.g., 20 kDa moieties). Aptamers were dissolved in a water/DMSO (1:1) solution to a concentration between 1.5 and 3mM. Sodium carbonate buffer, pH 8.5, was added to a final concentration of 100mM, and the oligo was reacted overnight with a 2.7 3.5 fold molar excess of the desired PEG reagent (e.g., 20 kDa Sunbright MENP-20T p nitrophenyl carbonate ester [NOF Corp, Japan]) dissolved in an equal volume of acetonitrile. The resulting 2 x 20 kDa PEGylated product was purified by ion exchange chromatography on Super Q 5PW (30) resin (Tosoh Biosciences), and desalted using reverse phase chromatography performed on Amberchrom CG300-S resin (Rohn and Haas), and lyophilized. 136 WO 2007/035922 PCT/US2006/037276 [00372] A general schematic of the resulting 5'-PEGylated aptamer is shown in Figure 27. The resulting bi-PEGylated aptamer sequence is listed below. Lower case letters "in", and "d" denote 2-0-methyl, and deoxy modifications respectively, "s" denotes an internucleotide phopshorothioate substitution, and "NH" denotes an amine to facilitate chemical coupling. 3'-5' -PEG Conjugate of anti-IL-23 aptamer ARC1623 ARC2350 (SEQ ID NO 320) PEG20K--nh-dAmCdAdGdGnCdAdAdGmUdAdAm UmUdGmGmG-s-dG-s-dA-s-dGmU-s dGmCmGmGdGmCdGdGmGmGmUdGmU-nh-PEG20K EXAMPLE 3: FUNCTIONAL CELL ASSAYS Cell-based assay and minimization of active rRfY IL-23 aptamers [003731 IL-23 plays a role in JAK/STAT signal transduction and phosphorylates STAT 1, 3, 4, and 5. To test whether IL-23 aptamers showed cell-based activity, signal transduction was assayed in the lysates of peripheral blood mononuclear cells (PBMCs) grown in media containing PHA (Phytohemagglutinin), or PHA Blasts. More specifically, the cell-based assay determined whether IL-23 aptamers could inhibit IL-23 induced STAT 3 phosphorylation in PHA Blasts. [00374] In essence, lysates of IL-23 treated cells will contain more activated STAT3 than quiescent or aptamer blocked cells. Inhibition of IL-23-induced STAT3 phosphorylation was measured by two methods: by western blot, using an anti-phospho-STAT3 Antibody (Tyr705) (Cell Signaling, Beverly, MA); and by TransAM m Assay (Active Motif, Carlsbad, CA). The TransAM7 assay kit provides a 96 well plate on which an oligonucleotide containing the STAT consensus binding site (5'TTCCCGGAA-3') is immobilized. An anti STAT3 antibody that recognizes an epitope on STAT3 that is only accessible when STAT3 is activated is used in conjunction with an HRP-conjugated secondary antibody to give a colorimetric readout that can be quantified by spectrophotometry. (See Figure 19). [00375] In summary, the cell-based assay was conducted by isolating the peripheral blood mononuclear cells (PBMCs) from whole blood using a Histopaque gradient (Sigma, St. Louis, MO). The PBMCs were cultured for 3 to 5 days at 37'C/5% CO 2 in Peripheral Blood Medium (Sigma) which contains PHA, supplemented with IL-2 (100 units/mL) 137 WO 2007/035922 PCT/US2006/037276 (R&D Systems, Minneapolis, MN), to generate PHA Blasts. To test IL-23 aptamers, the PHA Blasts were washed twice with IX PBS, then serum starved for four hours in RPMI, 0.20 % FBS. After serum starvation, approximately 2 million cells were aliquotted into appropriately labeled eppendorf tubes. hIL-23 at a final constant concentration of 3 ng/mL (R&D Systems, Minneapolis, MN) was combined with a dilution series of various IL-23 aptamers as described in Example 1, and the cytokine/aptamer mixture was added to the aliquotted cells in a final volume of 100 pl and incubated at 37'C for 10-12 minutes. The incubation reaction was stopped by adding 1 mL of ice-cold PBS with 1.5 mM Na 3

VO

4 . Cell lysates were made using the lysis buffer provided by the TransAM T m STAT 3 assay following the manufacturer's instructions. Figure 20 depicts a flow summary of the protocol used for the cell based assay. [003761 Parent aptamer and minimized IL-23 aptamers from the various selections with 2'-F pyrimidines-containing pools (rRfY), ribo/2'O-Me containing pools (rRmY), deoxy/2'O-Me containing pools (dRmY), and optimized dRmY aptamers were tested using the TransAM method. Example 3A: Cell Based Assay Results for parent and minimzed clones from rRfY selections [003771 Full length clones from the rRfY selection described in Example 1A, and select minimized rRfY clones that were described in Example 2A.1, were tested using the TransAM7' STAT3 activation assay. Table 34 summarizes the cell based assay data for IL 23 full length aptamers generated from the rRfY selections described in Example 1A. Table 35 summarizes the activity data of the rRfY minimized clones, described in Example 2A. 1, each compared to the activity of their respective parent (full length) clone. The minimized rRfY clones Fl min2 (SEQ ID NO 147), AlOmin5 (SEQ ID NO 139), Al0min6 (SEQ ID NO 140), B1Omin4 (SEQ ID NO 144), B1Omin5 (SEQ ID NO 145), Type1.4 (SEQ ID NO 151) and Typel.5 (SEQ ID NO 152) each outperformed their respective parent clones (see Figure 21), in addition to all of the full length rRfY clones when tested in the TransAM

T

" STAT3 activation assay. 138 WO 2007/035922 PCT/US2006/037276 [003781 Table 34: Cell Based Assay Results: Summary of rRfY Clones Tested Clone SEQ ID NO Name selection Western Blot TransAM TransAM IC 50 AMX86 27 C5 R8 h-IL-23 Yes Yes 3 pM AMX86 13 D5 R8 h-IL-23 Yes Yes > 5 M AMX86 16 D6 R8 h-IL-23 Yes Yes > 5 iM AMX86 24 E6 R8 h-IL-23 Yes No AMX86 22 F6 R8 h-IL-23 Yes No AMX86 18 A7 R8 h-IL-23 Yes No AMX86 25 H7 R8 h-IL-23 Yes No AMX86 35 B9 R8 X-IL-23 Yes No AMX86 32 C9 R8 X-IL-23 Yes No AMX86 33 G9 R8 X-IL-23 Yes No AMX86 39 H9 R8 X-IL-23 Yes Yes 250 nM AMX86 28 BlO R8 X-IL-23 Yes Yes 800 nM AMX86 36 G10 R8 X-IL-23 Yes Yes ~2 piM AMX86 37 Al1 R8 X-IL-23 Yes No AMX86 30 Dl1 R8 X-IL-23 Yes No AMX84 43 A10 RIO PN-IL-23 Yes Yes 400 nM AMX84 44 B10 R10 PN-IL-23 Yes Yes > 1 pLM AMX84 45 Al l R10 PN-IL-23 Yes Yes > 5 gM 139 WO 2007/035922 PCT/US2006/037276 AMX84 46 Fi1 RIO PN-IL-23 Yes Yes 250 nM AMX84 47 E12 RIO PN-IL-23 Yes Yes > 1 FM AMX84 48 C10 RIO PN-IL-23 No Yes 250 nM AMX84 49 C1l RIO PN-IL-23 No Yes 800 nM AMX84 50 G11 RIO PN-IL-23 No Yes 250 nM ARX83 platel 51 HI R12 PN-IL23 No Yes > 5 gM AMX91 52 Fli R10 PN-IL-23 No Yes 5 gM AMX91 53 G1 R10 PN-IL-23 No Yes 2 tM AMX91 54 E3 R10 PN-IL-23 No Yes > 5 gM AMX91 55 H3 R10 PN-IL-23 No Yes 50 nM AMX91 64 Gil R12 PN-IL23 No Yes 3 gM AMX9 1 65 C12 R12 PN-IL23 No Yes 50 nM AMX91 66 H12 R12 PN-IL23 No Yes 350 nM AMX91 56 B5 RIO PN-IL-23 No Yes 1 pM AMX91 57 A6 R10 PN-IL-23 No Yes 3 pM AMX91 58 G7 R12 PN-IL23 No Yes 150 nM AMX91 59 H7 R12 PN-IL23 No Yes 50 nM AMX91 60 B8 R12 PN-IL23 No Yes 450 nM AMX91 61 H8 R12 PN-IL23 No Yes 3 FLM 62 AMX91- R12 PN-IL23 No Yes 50 nM 140 WO 2007/035922 PCT/US2006/037276 G9 AMX91 63 D9 R12 PN-IL23 No Yes 150 nM [003791 Table 35: IL-23 2'F rRfY Minimized aptamer binding compared to parent aptamers. SEQ ID Clone Name

IC

50

IC

50 Full NO Selection W.Blot TransAM minimer Length F 11nin2 R10 PN-IL 147 23 No Yes 25 nM 250 Nm AlOmin5 R10 PN-IL 139 23 No Yes 300 nM 1 [tM AlOmin6 RIO PN-IL 140 23 No Yes 250 nM 1 pM B1Omin4 RIO PN-IL 144 23 No Yes 500 nM 700 nM BOmin5 RIO PN-IL 145 23 No Yes 80 nM 700 nM 151 Typel.4 N/A No Yes 80 nM N/A 152 Typel.5 N/A No Yes 80 nM N/A Example 3B: Cell Based Assay Results for parent and minimzed clones from first dRmY selections [003801 Parent clones from the dRmY selection described in Example IC, and minimized dRmY clones from this selection (described in Example 2A.2), were tested for activity using the TransAM M STAT3 activation assay. The three full length dRmY clones described in Example 1 C which showed the highest binding affinity for IL-23, ARC489 (SEQ ID NO 91), ARC490 (SEQ ID NO 92), ARC491 (SEQ ID NO 94) were tested. ARC 492 (SEQ ID NO 97) which exhibited no binding to IL-23 was used as a negative control. ARC489 (SEQ ID NO 91), and ARC491 (SEQ ID NO 94) showed comparable cell based activity in the TransAM" STAT3 activation assay and preliminary data indicate IC 50 's in the 50 nM-500 nM range (data not shown). [00381] The only minimized clone from the dRmY minimization efforts described in Example 2A.2 which showed binding to IL-23, ARC527 (SEQ ID NO 159), was tested in 141 WO 2007/035922 PCT/US2006/037276 the TransAM '" STAT3 activation assay and showed a decrease in assay activity compared to its respective full length ARC489 (SEQ ID NO 91) (data not shown). Example 3C: Cell Based Assay Results for parent and minimized clones from second dRmY selections [00382] Parent clones from the dRmY selection described in Example 1D, and minimized clones from this selection (described in Example 2A.3) that displayed high affinity to hIL-23 were screened for functionality in the TransAM" assay using an 8-point IL-23 titration from 0 to 3 pM in 3 fold dilutions in combination with a constant IL-23 concentration of 3 ng/mL. IC 50 s for the full length clones were calculated from the dose response curves. Figure 22 is an example of the dose response curves for the dRmY clones from the selection described in Example ID that displayed potent cell based activity in the TransAM7 . assay (ARC611 (SEQ ID NO 103), ARC614 (SEQ ID NO 105), ARC621 (SEQ ID NO 108), and ARC627 (SEQ ID NO 110)). [00383] Minimized dRmY clones (described in Example 2A.3) were screened for functionality and compared to their respective parent clone in the in the TransAM M assay.

IC

50 s were calculated from the dose response curves. Figure 23 is an example of the dose response curves for some the more potent minimized dRmY clones, ARC979 (SEQ ID NO 177), ARC980 (SEQ ID NO 178), ARC982 (SEQ ID NO 180), compared to the parent full length clones, ARC621 (SEQ ID NO 108) and ARC627 (SEQ ID NO 110). ARC979 (SEQ ID NO 177) consistently performed the best in the TransAM m assay, with an IC 50 of 40 nM +/- 10 nM when averaged over the course of three experiments. ARC792 (SEQ ID NO 162), ARC794 (SEQ ID NO 164), ARC795 (SEQ ID NO 165) also displayed potent activity in the TransAM " assay. Example 3D: Cell Based Assay Results for Optimized ARC979 Derivatives [003841 Several of the optimized ARC979 derivatives described in Example 2B.2 that displayed high affinity to hIL-23 were screened for their ability to inhibit IL-23 induced STAT 3 activation using the PHA Blast assay previously described. Inhibition of IL-23 induced STAT3 phosphorylation was measured using the Pathscan* Phospho-STAT3 (Tyr705) Sandwich ELISA Kit (Cell Signaling Technology, Beverly, MA). 142 WO 2007/035922 PCT/US2006/037276 [003851 Similar to the TransAM" Assay method previously described, the Pathscan* Phospho-STAT3 (Tyr705) Sandwich ELISA Kit detects endogenous levels of Phospho STAT3 (Tyr705) protein by using a STAT3 rabbit monoclonal antibody which has been coated onto the wells of a 96-well plate. After incubation with cell lysates, both nonphospho- and phospho-STAT3 proteins are captured by the coated antibody. A phospho-STAT3 mouse monoclonal antibody is added to detect the captured phospho STAT3 protein, and an HRP-linked anti-mouse antibody is then used to recognize the bound detection antibody. HRP substrate, TMB, is added to develop color, and the magnitude of optical density for this developed color is proportional to the quantity of phospho-STAT3 protein. [00386] PHA Blasts were isolated and prepared as described above and treated with hIL 23 at a final constant concentration of 6 ng/mL (R&D Systems, Minneapolis, MN) to induce STAT3 activation, instead of using 3 ng/mL as previously described with the TransAM assay. Clones were screened by using a 6-point IL-23 titration from 0 to 700nM in 3 fold dilutions in combination with a constant IL-23 concentration of 6 ng/mL of IL-23 (R&D Systems, Minneapolis, MN) to induce STAT3 activation, instead of using 3 ng/mL as previously described with the TransAMm assay. Lysates of treated cells were prepared using the buffers provided by the Pathscan kit, and the assay was run according to the manufacturer's instructions. IC 5 os for the full length clones were calculated from the dose response curves. [003871 ARC979, which displayed an IC 50 of 40 +/-10 nM using the TransAM" method, consistently displayed an IC 50 of 6 +/- 1 nM using the Pathscan* method. As previously mentioned this IC 50 value is consistent with the KD value for ARC979 of 1 nM which was repeatedly verified under the direct binding assay conditions described in Example 2B.2. As can be seen from the Table 36, several of the optimized derivatives of ARC979 remarkably displayed even higher potentcy than ARC979 when directly compared using the Pathscan* Method, particularly ARC1624 and ARC1625, which gave IC 50 values of 2 nM and 4 nM respectively. [00388] Figure 24 is an example of the dose response curves for several of the optimized clones that displayed both high affinity for IL-23 and potent cell based activity in the Pathscan* assay. Table 36 summarizes the IC 50 's derived from the dose response curves for the optimized aptamers tested. 143 WO 2007/035922 PCT/US2006/037276 [003891 Table 36: IC 50 s for Optimized ARC979 derivatives in the Pathscan* Assay SEQ ID NO Clone Pathscan* IC 50 (nM) 177 979 6+/-1 275 1544 ___ 308 1622 9 309 1623 5 310 1624 2 311 1625 4 312 1626 12 313 1755 68 314 1756 19 Example 3E: Cell based assay results for PEGylated anti-IL-23 aptamer ARC 1988 Pathscan* [003901 The 5'-PEGylated aptaner, ARC1988 (ARC1623 with a 40 kDa PEG conjugated to the 5' end) (SEQ ID NO 317) was tested simultaneously with its unPEGylated counterpart, ARC 1623 (SEQ ID NO 309), in the Pathscan assay described in Example 3D above. As can be seen from Figure 28, ARC 1988 was more potent in the Pathscan assay as compared to unPEGylated, ARC 1623. IL-17 Production by Mouse Splenocytes [003911 ARC1988 (SEQ ID NO 317) was also tested simultaneously with ARC1623 (SEQ ID NO 309) in an ex vivo splenocyte assay designed to measure the ability of the aptamers to inhibit IL-23/IL-2 induced IL-17 production by mouse splenocytes. Splenocytes were prepared as follows. The spleens from 2 CD-2 female mice (6-8 weeks old) (Charles 144 WO 2007/035922 PCT/US2006/037276 River Labs, Wilmington, MA) were removed (after euthanization) and transferred into a medium Petri dish. Cells were dissociated from the spleens using the blunt end of a 3 mL syringe to mash the spleens. After dissociation, the cells were collected and transferred into a 50 mL tube and centrifuged at 1200 rpm to pellet the cells. After centrifugation, the pelleted cells were resuspended in 5 mL of lysis buffer (Biosource, Camarillo, CA, cat # p304-100) and incubated for 5 minutes at room temperature to lyse the red blood cells. Following lysis, the cells were brought up to a final volume of 50 mL using RPMI Medium 1640 (Gibco (Invitrogen), Carlsbad, CA cat # 07599) and centrifuged at 1200 rpm for 5 minutes to pellet cells. The pelleted, lysed cells were resuspended in 10 mL of RPMI 1640. The lysed cells were then counted and plated at a density of 4x1 05 cells/wel in a final volume of 50 ptL 1 in a 96 well Microtest Tissue Culture plate (Falcon (BD Biosciences, San Jose, CA), cat # 353072). {00392] IL-23 and IL-2 were used to induce the IL- 17 production by the mouse splenocytes, and a e human IL-12 (p 4 0) antibody (Pharmigen (BD Biosciences, San Jose, CA) cat # 554659) and a mouse IgG (Pharmigen cat # 554721) were used as positive and negative controls for the ARC1988 aptamer. 50 pl of IL-2 (20,000 U/mL) and IL-23 (200 ng/mL) were added to each well for a final concentration of 5000 U/mL 50 ng/mLrespectively. 50 pLL of either aptamer (4 uM) or control antibody (800 ng/mL) were added to appropriate wells, for a final concentration of luM and 200 ng/mL respectively. RPMI-l 640 was added to each well to bring the final volume up to 200 p1/well. These plated and treated cells were incubated at 37' C for 24 hours, then either frozen at -20* C for later quantification, or quantified immediately. IL- 17 production was quantified by ELISA (Quantikine Murine IL-17 kit cat. # M1700, R&D Systems, Minneapolis, MN) following the manufacturer's recommended protocol. 1003931 As can be seen from Figure 29, ARC1988 (40kDa PEG) inhibited IL-23 induced IL- 17 production in mouse splenocytes in a dose dependent manner with a calculated IC 50 of 27 nM, whereas the ARC 1623 (no PEG) had no effect on IL-23 induced IL-17 production in mouse splenocytes. This result is consistent with the increase in activity conferred by PEG conjugation as seen with ARC 1988 as compared to ARC1623 in the Pathscan Assay described immediately above. 145 WO 2007/035922 PCT/US2006/037276 IL-12 and IL-23 dependent Interferon Gamma production by PHA Blasts [00394] ARC1988 (SEQ ID NO 317) was also tested in an assay designed to the ability of anti-IL-23 aptamers to inhibit IL-12/IL- 18 or IL-23/IL-18 dependent IFN-y production in PHA Blasts. [003951 PHA Blasts were isolated and prepared as described above. Once isolated, PHA Blasts were cultured for 4 days before use (with no re-feeding the night before use). After culturing for 4 days, an appropriate number of cells (enough for 0.5 x106 cells per well) were collected, pelleted by centrifugation and washed with RPMI 1640 and .2% FBS (repeated twice). These cells were then serum starved by placement into 2, 150 mm sterile culture dishes with 25 mL of RPMI 1640-.2% FBS each for 2-3 hours. Following serum starvation, cells were plated in a 96 well microtiter plate at a density of 0.5x1 06 cells per 200 il of serum starved media. [00396] IL-12/IL-18 or IL-23/IL-18 was used to induce IFN-y production in PHA Blasts as follows. 10 g of IL-23 (R&D Systems) at a concentration of 60 ng/mL (or 10 fl of IL-12 at a concentration of 20 ng/mL), and 10 pL1 of IL-18 (MBL) at a concentration of 200 ng/mL were added to the appropriate wells. A 10 point serial dilution of ARC1988 (1:3 dilutions, 0-60 uM) was prepared in serum starved media, and 10 [l of each concentration were added to appropriate wells. The final volume in each well of plated cells was 230 p, each containing the following final concentrations: IL-23~3 ng/mL (or IL- 12 1 ng/mL); IL-18 1 I ng/mL; ARC1988 titration ~ 0-3 uM. A c human IL-12 (p40) antibody (Pharmigen (BD Biosciences, San Jose, CA) cat # 554659) and a mouse IgG antibody (Pharmigen (BD Biosciences, San Jose, CA) cat # 554721) were used as positive and negative controls. All points were tested in duplicate. PHA Blasts were incubated with treatment for 24 hours at 37"C. Following incubation, 200 [d of supernatant was removed from each well and either flash frozen at -80*C, or quantified immediately for IFN-y. An ELISA kit was used to quantify the IL-23/IL-18 and IL-12/IL-18 induced IFN-y in PHA Blasts according to the manufacturer's recommended protocol (Recombinant human IFN- y Quantikine Kit, R&D Systems, Minneapolis, MN). The colorimetric readout was quantified using a 96 well plate reader and absorbance values were graphed. Figure 30 shows that ARC1988 inhibits both IL-23/IL-1 8 and IL-1 2/IL-1 8 induced production of IFN- y in a dose dependent manner, with a calculated IC50 of -4 nM and ~122 nM respectively, indicating that ARC1988 is more specific for IL-23 than IL-12, as expected. 146 WO 2007/035922 PCT/US2006/037276 Example 3G: Cell based assay results for parent and minimized clones from the mouse IL 23 selections [00397] Using the PHA Blast assay and the TransAM method described above, mouse IL-23 was shown to activate STAT3 in human PHA blasts (See Figure 25). Therefore, the ability of the parent clones from the mouse IL-23 selection described in Example 1E, and minimized clones from this selection (described in Example 2A.4) that displayed affinity to mIL-23 to block mouse IL-23 induced STAT3 activation in human PHA blast cells was measured using the TransAM " assay. The protocol used was identical to that previously described except mouse IL-23 was used to induce STAT 3 activation in PHA Blasts at a concentration of 30 ng/mL, instead of using human IL-23 at a concentration of 3 ng/mL. The results for the parent clones are listed in Table 37 and the results for the minimized clones are listed in Table 38 below. [003981 Table 37: Parent mIL-23 -rRfY Clone Activity in the TransAM" Assay SEQ ID NO Clone Name Selection IC 50 (nM) 124 ARC1628 R7 mIL-23 37 125 ARC1629 R7 mIL-23 Not Tested 126 ARC1630 R7 mIL-23S 16.6* 127 ARC1631 R7 mIL-23S Not Tested 128 ARC1632 R7 mIL-23S 18 129 ARC1633 R7 mIL-23S 31 130 ARC1634 R7 mIL-23S 9 * Multiple experiment average. [00399] Table 38: Mouse IL-23 rRfY Minimized Clone Activity in the TransAM Assay Minimized Clone Parent IC 50 mIL-23 SEQ ID NO Clone (nM) 199 ARC1628 18 nM 200 ARC1632 inactive 201 ARC1633 7 202 ARC1634 26 147 WO 2007/035922 PCT/US2006/037276 The invention having now been described by way of written description and example, those of skill in the art will recognize that the invention can be practiced in a variety of embodiments and that the description and examples above are for purposes of illustration and not limitation of the following claims. 148

Claims (22)

1. An aptamer that binds to IL-23, wherein the aptamer inhibits IL-23 induced STAT 3 phosphorylation and the aptamer is SEQ ID NO: 309 or an aptamer that has the same ability to inhibit IL-23 induced STAT 3 phosphorylation as SEQ ID NO: 309 and wherein the aptamer comprises a KD less than 100nM.

2. The aptamer of claim 1, wherein the aptamer having the same ability to inhibit IL-23 induced STAT 3 phosphorylation is selected from the group consisting of: SEQ ID NOS: 306 to 308 and SEQ ID NOS: 310 to 314.

3. The aptamer of claim 1, wherein the aptamer binds human IL-23.

4. The aptamer of claim 1, wherein the aptamer is further modified to comprise at least one chemical modification.

5. The aptamer of claim 4, wherein the modification is selected from the group consisting of: a chemical substitution at a sugar position; a chemical substitution at a phosphate position; and a chemical substitution at a base position, of the nucleic acid.

6. The aptamer of claim 1, wherein the modification is selected from the group consisting of: incorporation of a modified nucleotide, 3' capping, conjugation to a high molecular weight, non-immunogenic compound, and conjugation to a lipophilic compound.

7. The aptamer of claim 6, wherein the non-immunogenic, high molecular weight compound is polyalkylene glycol.

8. The aptamer of claim 7, wherein the polyalkylene glycol is polyethylene glycol.

9. The aptamer of claim 1, wherein the aptamer inhibits IL-23 induced STAT 3 phosphorylation in vitro.

10. An aptamer that binds to IL-23 and comprises an aptamer nucleic acid sequence that is at least 95 % identical to SEQ ID NO: 309.

11. The aptamer of claim 10, comprising the aptamer nucleic acid sequence set forth in SEQ ID NO: 309.

12. The aptamer of claim 11, further comprising a PEG.

13. The aptamer of claim 12, wherein the PEG comprises a molecular weight selected from ther group consisting of 20 and 40 kDA. 149 WO 2007/035922 PCT/US2006/037276

14. An aptamer having the structure set forth below: 0 ii H O-C-N- 5' Aptamer 3' 20 kDa mPEG-O 20 kDa mPEG-O wherein: indicates a linker Aptamer = dAmCdAdGdGmCdAdAdGmUdAdAmUmUdGmGmG-s-dG-s-dA-s-dGmU-s dGmCmGmGdGmCdGdGmGmGmUdGmU- 3 T (SEQ ID NO: 309) wherein "d" indicates a 2' deoxy nucleotide, "m" indicates a 2'-Ome nucleotide, s indicates a phosphorothioate substitution at a non-bridging phosphate position and 3T indicates an inverted deoxy thymidine.

15. The aptamer of claim 14, wherein the linker is an alkyl linker.

16. The aptaemr of claim 15, wherein the alkyl linker comprises 2 to 18 consecutive CH 2 groups.

17. The aptaemr of claim 16, wherein the alkyl linker comprises 2 to 12 consecutive CH 2 groups.

18. The aptaemr of claim 17, wherein the alkyl linker comprises 3 to 6 consecutive CH2 groups.

19. The aptamer of claim 18, having the structure set forth below: 0 O 0-C-N -5 er 3' 20 kDa mPEG-O- H 0-5'Aptam 20 kDa mPEG-O Aptamer = dAnCdAdGdGmCdAdAdGmUdAdAmUiUdGmGmG-s-dG-s-dA-s-dGmU-s dGmCmGmGdGmCdGdGmGmGmlUdGmU-3T (SEQ ID NO: 309) 150 WO 2007/035922 PCT/US2006/037276 wherein "d" indicates a 2' deoxy nucleotide, "in" indicates a 2'-Ome nucleotide, s indicates a phosphorothioate substitution at a non-bridging phosphate position and 3T indicates an inverted deoxy thymidine.

20. A composition comprising a therapeutically effective amount of the aptaner of claim 1 or a salt thereof and a pharmaceutically acceptable carrier or diluent.

21. A method of treating, preventing or ameliorating a disease mediated by 11-23 comprising administering the aptamer of claim 19 to a patient in need thereof.

22. A diagnostic method comprising contacting an aptamer of claim 1 with a test composition and detecting the presence or absence of IL-23. 151